diff --git a/lib/Board.cpp b/lib/Board.cpp
index 9a169ba..db7c081 100644
--- a/lib/Board.cpp
+++ b/lib/Board.cpp
@@ -59,13 +59,16 @@ static Cell cellAtPosition(GridPosition point) {
   return Cell(board[point.y][point.x]);
 }
 
+bool isWall(GridPosition point) {
+  return cellAtPosition(point) == Cell::wall;
+}
+
 bool isWalkableForPacMan(GridPosition point) {
-  return cellAtPosition(point) != Cell::wall && cellAtPosition(point) != Cell::pen;
+  return !isWall(point) && !isInPen(point);
 }
 
 bool isWalkableForGhost(GridPosition target_position, GridPosition current_position, bool isEyes) {
-  const Cell cell = cellAtPosition(target_position);
-  if (cell == Cell::wall)
+  if (isWall(target_position))
     return false;
   return isEyes || isInPen(current_position) || !isInPen(target_position);
 }
diff --git a/lib/Canvas.cpp b/lib/Canvas.cpp
index cac63ee..0c50c83 100644
--- a/lib/Canvas.cpp
+++ b/lib/Canvas.cpp
@@ -36,9 +36,10 @@ void Canvas::render(const GameState & gameState) {
   renderPellets(gameState.pellets);
   renderSuperPellets(gameState.superPellets);
 
-  renderGhost(gameState.blinky);
-  renderGhost(gameState.pinky);
-  renderGhost(gameState.inky);
+  renderGhost(gameState.ghosts.blinky);
+  renderGhost(gameState.ghosts.pinky);
+  renderGhost(gameState.ghosts.inky);
+  renderGhost(gameState.ghosts.dave);
 
   renderScore(gameState.score.points);
   renderLives(gameState.score.lives);
diff --git a/lib/Dave.cpp b/lib/Dave.cpp
new file mode 100644
index 0000000..1520855
--- /dev/null
+++ b/lib/Dave.cpp
@@ -0,0 +1,38 @@
+#include "Dave.hpp"
+
+namespace pacman {
+
+Dave::Dave()
+  : Ghost(Atlas::Ghost::dave) {
+  pos = initialPosition();
+}
+
+double Dave::speed() const {
+  if (state == State::Eyes)
+    return 2;
+  if (state == State::Frightened)
+    return 0.5;
+  return 0.75;
+}
+
+void Dave::setTarget(Position pacManPos) {
+  if (isInPen()) {
+    target = penDoorPosition();
+    return;
+  }
+  if (positionDistance(pos, pacManPos) > 8) {
+    target = pacManPos;
+  } else {
+    target = scatterTarget();
+  }
+}
+
+Position Dave::initialPosition() const {
+  return { 15.5, 14 };
+}
+
+Position Dave::scatterTarget() const {
+  return { 0, 30 };
+}
+
+} // namespace pacman
diff --git a/lib/Game.cpp b/lib/Game.cpp
index 6d9f864..d3333ab 100644
--- a/lib/Game.cpp
+++ b/lib/Game.cpp
@@ -40,6 +40,9 @@ void Game::processEvents(InputState & inputState) {
   if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) {
     inputState.enableAI = !inputState.enableAI;
   }
+  if (sf::Keyboard::isKeyPressed(sf::Keyboard::Q)) {
+    exit(0);
+  }
 
   inputState.down = sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Down);
   inputState.up = sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Up);
diff --git a/lib/GameState.cpp b/lib/GameState.cpp
index b47523c..c25cc85 100644
--- a/lib/GameState.cpp
+++ b/lib/GameState.cpp
@@ -18,18 +18,11 @@ void GameState::step(std::chrono::milliseconds delta) {
   if (!pacMan.hasDirection())
     return;
 
-  blinky.setTarget(pacMan.position());
-  blinky.update(delta);
-  pinky.setTarget(pacMan.positionInGrid(), pacMan.currentDirection());
-  pinky.update(delta);
-  inky.setTarget(pacMan.positionInGrid(), pacMan.currentDirection(), blinky.positionInGrid());
-  inky.update(delta);
+  ghosts.setTarget(pacMan.positionInGrid(), pacMan.currentDirection());
+  ghosts.update(delta);
 
   fruit.update(delta, score.eatenPellets);
-
-  checkCollision(blinky);
-  checkCollision(pinky);
-  checkCollision(inky);
+  ghosts.checkCollision(*this);
 
   eatPellets();
   eatFruit();
@@ -55,9 +48,7 @@ void GameState::handleDeathAnimation(std::chrono::milliseconds delta) {
   timeSinceDeath += delta;
 
   if (timeSinceDeath.count() > 1000) {
-    blinky.reset();
-    pinky.reset();
-    inky.reset();
+    ghosts.reset();
     pacMan.reset();
     pacManAI.reset();
     timeSinceDeath = std::chrono::milliseconds(0);
@@ -74,10 +65,7 @@ void GameState::eatPellets() {
   if (superPellets.eatPelletAtPosition(pos)) {
     score.eatenPellets++;
     score.points += POWER_PELLET_POINTS;
-
-    blinky.frighten();
-    pinky.frighten();
-    inky.frighten();
+    ghosts.frighten();
   }
 }
 
diff --git a/lib/GhostState.cpp b/lib/GhostState.cpp
new file mode 100644
index 0000000..ffb61ae
--- /dev/null
+++ b/lib/GhostState.cpp
@@ -0,0 +1,41 @@
+#include "GhostState.hpp"
+#include "GameState.hpp"
+
+namespace pacman {
+
+void GhostState::setTarget(GridPosition pacManPosition, Direction pacManDirection) {
+  blinky.setTarget(gridPositionToPosition(pacManPosition));
+  pinky.setTarget(pacManPosition, pacManDirection);
+  inky.setTarget(pacManPosition, pacManDirection, blinky.positionInGrid());
+  dave.setTarget(gridPositionToPosition(pacManPosition));
+}
+
+void GhostState::update(std::chrono::milliseconds delta) {
+  blinky.update(delta);
+  pinky.update(delta);
+  inky.update(delta);
+  dave.update(delta);
+}
+
+void GhostState::checkCollision(GameState & gameState) {
+  gameState.checkCollision(blinky);
+  gameState.checkCollision(pinky);
+  gameState.checkCollision(inky);
+  gameState.checkCollision(dave);
+}
+
+void GhostState::reset(void) {
+  blinky.reset();
+  pinky.reset();
+  inky.reset();
+  dave.reset();
+}
+
+void GhostState::frighten(void) {
+  blinky.frighten();
+  pinky.frighten();
+  inky.frighten();
+  dave.frighten();
+}
+
+} // namespace pacman
diff --git a/lib/PacManAI.cpp b/lib/PacManAI.cpp
index 4688b15..c605b6b 100644
--- a/lib/PacManAI.cpp
+++ b/lib/PacManAI.cpp
@@ -16,22 +16,28 @@ Direction PacManAI::suggestedDirection() const {
 
 // This function is not yet implemented.
 // You will implement it as part of module 25.
-GridPosition PacManAI::pelletClosestToPacman(GridPosition,
-                                             std::vector<GridPosition> &) {
-
-    return {0, 0};
+GridPosition PacManAI::pelletClosestToPacman(GridPosition position,
+                                             std::vector<GridPosition> & pellets) {
+  if (pellets.empty())
+    return { 0, 0 };
+  return *std::min_element(pellets.begin(), pellets.end(), [position](GridPosition a, GridPosition b) {
+    return positionDistance(a, position) < positionDistance(b, position);
+  });
 }
 
 // This function is not yet implemented.
 // You will implement it as part of module 25.
-bool PacManAI::isValidMove(const Move &) {
-    return false;
+bool PacManAI::isValidMove(const Move & move) {
+  return isWalkableForPacMan(move.position) && move.direction != oppositeDirection(direction);
 }
 
 // This function is not yet implemented.
 // You will implement it as part of module 25.
-Direction PacManAI::optimalDirection(const std::array<Move, 4> &) {
-  return Direction::NONE;
+Direction PacManAI::optimalDirection(const std::array<Move, 4> & moves) {
+  auto bestMove = std::min_element(moves.begin(), moves.end(), [](Move a, Move b) {
+    return a.distanceToTarget < b.distanceToTarget;
+  });
+  return bestMove->direction;
 }
 
 void PacManAI::update(const PacMan & pacMan, const Pellets & pellets) {
diff --git a/lib/include/Atlas.hpp b/lib/include/Atlas.hpp
index 6a70cd8..747fd2a 100644
--- a/lib/include/Atlas.hpp
+++ b/lib/include/Atlas.hpp
@@ -12,7 +12,7 @@ enum class Ghost : unsigned int {
   blinky = 2,
   pinky = 3,
   inky = 4,
-  clyde = 5,
+  dave = 5,
 };
 
 constexpr GridPosition pacman_right_wide = { 0, 0 };
@@ -46,7 +46,7 @@ constexpr GridPosition eyeSprite(Direction direction) {
 }
 
 constexpr GridPosition ghostSprite(Ghost ghost, Direction direction, bool alternative) {
-  assert(ghost >= Ghost::blinky && ghost <= Ghost::clyde && "Invalid Ghost");
+  assert(ghost >= Ghost::blinky && ghost <= Ghost::dave && "Invalid Ghost");
   auto y = static_cast<size_t>(ghost);
   size_t x = 0;
   switch (direction) {
diff --git a/lib/include/Board.hpp b/lib/include/Board.hpp
index ae24e7b..d0ae875 100644
--- a/lib/include/Board.hpp
+++ b/lib/include/Board.hpp
@@ -8,6 +8,7 @@
 
 namespace pacman {
 
+bool isWall(GridPosition point);
 bool isWalkableForPacMan(GridPosition point);
 bool isWalkableForGhost(GridPosition target_position, GridPosition current_position, bool isEyes);
 bool isInPen(GridPosition point);
diff --git a/lib/include/Dave.hpp b/lib/include/Dave.hpp
new file mode 100644
index 0000000..935fb96
--- /dev/null
+++ b/lib/include/Dave.hpp
@@ -0,0 +1,20 @@
+#pragma once
+
+#include "Ghost.hpp"
+
+namespace pacman {
+
+class Dave final : public Ghost {
+public:
+  Dave();
+  void setTarget(Position pacManPos);
+
+protected:
+  double speed() const override;
+  Position initialPosition() const override;
+
+private:
+  Position scatterTarget() const;
+};
+
+} // namespace pacman
diff --git a/lib/include/GameState.hpp b/lib/include/GameState.hpp
index 65f1183..2837e54 100644
--- a/lib/include/GameState.hpp
+++ b/lib/include/GameState.hpp
@@ -1,8 +1,10 @@
 #pragma once
 
 #include "Blinky.hpp"
+#include "Dave.hpp"
 #include "Fruits.hpp"
 #include "Ghost.hpp"
+#include "GhostState.hpp"
 #include "Inky.hpp"
 #include "InputState.hpp"
 #include "PacMan.hpp"
@@ -17,9 +19,7 @@ namespace pacman {
 struct GameState {
   void step(std::chrono::milliseconds delta);
 
-  Blinky blinky;
-  Pinky pinky;
-  Inky inky;
+  GhostState ghosts;
 
   PacMan pacMan;
   PacManAI pacManAI;
diff --git a/lib/include/GhostState.hpp b/lib/include/GhostState.hpp
new file mode 100644
index 0000000..7b862b4
--- /dev/null
+++ b/lib/include/GhostState.hpp
@@ -0,0 +1,26 @@
+#pragma once
+
+#include "Blinky.hpp"
+#include "Dave.hpp"
+#include "Inky.hpp"
+#include "Pinky.hpp"
+
+namespace pacman {
+
+class GameState;
+
+class GhostState {
+public:
+  void setTarget(GridPosition pacManPosition, Direction pacManDirection);
+  void update(std::chrono::milliseconds delta);
+  void checkCollision(GameState & gameState);
+  void reset();
+  void frighten();
+
+  Blinky blinky;
+  Pinky pinky;
+  Inky inky;
+  Dave dave;
+};
+
+} // namespace pacman
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index ad6067e..96f48ef 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -8,4 +8,4 @@ target_link_libraries(pacman_tests Catch2::Catch2 libpacman)
 
 # This setup the tests on CI. We disable the AI tests
 # because you will have to implement them.
-add_test(NAME pacman_tests COMMAND pacman_tests "~[AI]")
+add_test(NAME pacman_tests COMMAND pacman_tests)
diff --git a/test/testBoard.cpp b/test/testBoard.cpp
index c9c6fb5..8e296a1 100644
--- a/test/testBoard.cpp
+++ b/test/testBoard.cpp
@@ -65,4 +65,15 @@ TEST_CASE("Teleport", "[board]") {
     const pacman::GridPosition result = pacman::teleport(portalLeft);
     REQUIRE(result.x == portalRight.x);
   }
-}
\ No newline at end of file
+}
+
+TEST_CASE("Is wall", "[board]") {
+  REQUIRE(pacman::isWall(pacman::GridPosition{ 0, 0 }));
+  REQUIRE(pacman::isWall(pacman::GridPosition{ 27, 30 }));
+  REQUIRE(!pacman::isWall(pacman::GridPosition{ 1, 1 }));
+  REQUIRE(!pacman::isWall(pacman::GridPosition{ 26, 29 }));
+  REQUIRE(!pacman::isWall(pacman::GridPosition{ 0, 14 }));
+  REQUIRE(!pacman::isWall(pacman::GridPosition{ 27, 14 }));
+  REQUIRE(!pacman::isWall(pacman::GridPosition{ 11, 13 }));
+  REQUIRE(!pacman::isWall(pacman::GridPosition{ 16, 15 }));
+}
diff --git a/test/testPacmanAI.cpp b/test/testPacmanAI.cpp
index 4d429fb..4e9e609 100644
--- a/test/testPacmanAI.cpp
+++ b/test/testPacmanAI.cpp
@@ -7,6 +7,7 @@ TEST_CASE("Find pellet closest to PacMan", "[AI]") {
     PacManAI AI;
     using TestData = std::tuple<GridPosition, std::vector<GridPosition>, GridPosition>;
     auto data = GENERATE(
+                TestData{{5, 5}, {}, {0, 0}},
                 TestData{{5, 5}, {{5, 6}}, {5, 6}},
                 TestData{{5, 5}, {{5, 5}}, {5, 5}},
                 TestData{{5, 5}, {{0, 0}, {5, 6}}, {5, 6}},