Complex sentence: The two continue to attend the games together until one night in the summer when Lindsay, who has a lot of work to catch up on takes her laptop to the game, and after not paying attention, gets knocked out by a line drive foul ball.
Split into simpler sentences: The two continue to attend the games together until one summer night when Lindsay attempts to catch up on work by taking her laptop to the game. After not paying attention to the game, she gets knocked out by a line drive foul ball.