Bobby and his team respond to an emergency at a children's birthday party that leaves lives hanging in the balance. Chim and Bobby get into a heated argument about Bobby not talking about his family. Bobby finally tells Chim that his relationship is full of lies. Chim leaves the firehouse to go get some air. Later, The crew jumps into action after Chim is involved in a devastating accident. Athena tries to cope with a tragedy that hits way too close to home and Abby is confronted with a life-changing decision for her mother and makes a connection with Buck.