Sully lives his worst nightmare as the police search the city for a man who is buried alive and whose kidnappers are involved in a fatal car crash; Kim and Bobby find an abandoned 4 year old boy wandering the streets; Sully's mother wanders off from her nursing home; Carlos adopts a deceased patient's cockatoo.

Ty, Sully, Bosco, and Faith rush to the scene of a school shooting; Sully and Tatiana ponder their future together; Kim continues to struggle with her depression.

No one can find Bosco after a sexual assault suspect is found dead. While Bosco spends time with family, Yokas, Ty and Sully try to clear him as a murder suspect. Still locked in a custody battle over Joey, Jimmy and Kim meet with a court-appointed evaluator and plead their cases. Alex tries to stay busy to avoid dealing with her feelings about her father's death.

After seeing his young son Joey fall and break his arm in a playground accident, Jimmy fights through a burning apartment building to save a frightened boy of Joey's age. Meanwhile, a guilt-ridden Doc can't stay away from a recuperating teenager, Ryan Buckley, who was accidentally paralyzed while under Doc's care. Taylor is annoyed by a new probationary firefighter, Ken Prescott. Bosco and Yokas search for a drug addict who murdered his girlfriend.