After Stabler is injured by a perp at work, Benson teams up with Munch and Tutuola to look into a mysterious envelope of pictures.
When a suspect confesses to murdering a celebrity chef, Baez and Danny don't believe him; a longtime friend's request for help puts Frank in a tough position.
Boden discovers that a fire at his wife's school wasn't a mistake; one of Brett's childhood friends comes to visit; Dawson reconnects with Casey; after being evicted, Kidd turns to Severide.
Mouch gets a little too competitive in the firefighter muster challenge; Chief Boden dials up the pressure on Casey and Severide to look into the cause of the fire that trapped his wife.
A top surgeon who has to operate on the president is held hostage with her family by a rogue FBI agent who demands that she kill the President or else he'll kill her family.