Timeline was a film based on the best selling Michael Crichton novel of the same title. Adam and Liam were both fans of the book and saw the movie shortly after it was released in theaters. The film was so awful, Adam couldn't stop laughing at parts.
In one part of the film, the time travelers are tied up and forced to walk to some place, and an old man goes, "OH MY GOD!!" in an Irish accent after one of his colleagues is suddenly killed by a bad guy. In another part, the guys attacking the castle decide to light their arrows on fire. After a while, you just accept the fire arrows as the normal way to attack the castle. Then, they come up with a great plan: TO FIRE ARROWS THAT ARE NOT FLAMING SO THEY CAN'T SEE THEM IN THE DARK. So they fire the first barrage, and some guy yells "NIGHT ARROWS!" even though they're just regular arrows.
It was the hardest Adam ever laughed in a movie theatre. The entire movie, Liam was just looking over at Adam whenever he was laughing because he thought he was crazy. It was later revealed that Adam was thinking about another terrible movie with a similar plotline, Black Knight, the entire time.