Shocking information threatens Jack Dayton’s surgery and the future of OR 2.0. Archer goes rogue to save a patient in need. Maggie questions her future at Med.

Will Halstead returns to Med to help Goodwin with a secret investigation. Archer and Charles deal with twins who insist on being identical inside and out. Stevie and Dylan treat…

Truck and squad are called to aid in a massive all-city response when an old, ill-equipped factory-turned live/work space quickly turns into a firestorm, trapping countless unsuspecting victims. The dire…

The surprising arrival of a new fire truck brings both joy and chaos to members of Firehouse 51. Boden and Severide are asked to make peace with an old foe…

A rare but deadly bacteria takes its toll on numerous victims around the city, leaving Chicago’s finest first responders to work together alongside the CDC to resolve the dangerous situation….

Firehouse 51 is faced with a daunting challenge when an out-of-control blaze consumes a 15-story apartment complex, trapping victims on the top floors. Complicating the rapidly escalating situation, members soon…

When Burgess and Lindsay respond to a call about a stabbing, the assailant turns out to be a kidnapping victim escaping her captor; Ruzek accuses Roman of having feelings for…

Responding to a call about a suspicious duffel bag at the Chicago Lakefront, Voight is horrified to discover that the bag contains the frigid and unmoving body of a newborn…

Intelligence investigates a doctor who gave his patients lethal doses of chemotherapy. Roman fights a wrongful shooting investigation. The crossover starts on Chicago Fire S04E10 The Beating Heart (I) and…

After years of questions and mystery surrounding the night Alison DiLaurentis disappeared, The Liars finally learn what really happened to her that September night.

Ali considers a plea deal, but it incriminates someone else, so the girls try to help her and Mike, as well as themselves. Elsewhere, Spencer unwinds while on a night…

Melissa reveals her knowledge of Alison’s disappearance to Spencer; Emily seeks Ezra’s help.

Aria watches over Ezra at the hospital, while Alison and the others set a trap for “A.”

Alison struggles with the death of her mother, as the Liars try to navigate through her new lie.

Aria searches for information on a patient; Spencer borrows Ezra’s spy equipment.

The Liars try to prevent Alison from sending an innocent man to jail; Hanna seeks a normal life.

Hanna worries that her mother is keeping a dangerous secret and is determined to protect her at all costs, which leads to an uncomfortable meeting with Detective Holbrook.

Holbrook’s partner, Lt Tanner, comes to town, intensifying their investigation into the Liars and their possible connection to Wilden’s death.

Ali considers a plea deal, but it incriminates someone else, so the girls try to help her and Mike, as well as themselves. Elsewhere, Spencer unwinds while on a night…

Alison struggles with the death of her mother, as the Liars try to navigate through her new lie.

Aria searches for information on a patient; Spencer borrows Ezra’s spy equipment.

The Liars try to prevent Alison from sending an innocent man to jail; Hanna seeks a normal life.

Melissa reveals her knowledge of Alison’s disappearance to Spencer; Emily seeks Ezra’s help.

After years of questions and mystery surrounding the night Alison DiLaurentis disappeared, The Liars finally learn what really happened to her that September night.

Hanna worries that her mother is keeping a dangerous secret and is determined to protect her at all costs, which leads to an uncomfortable meeting with Detective Holbrook.

Holbrook’s partner, Lt Tanner, comes to town, intensifying their investigation into the Liars and their possible connection to Wilden’s death.

Aria watches over Ezra at the hospital, while Alison and the others set a trap for “A.”

Ali considers a plea deal, but it incriminates someone else, so the girls try to help her and Mike, as well as themselves. Elsewhere, Spencer unwinds while on a night…

Aria searches for information on a patient; Spencer borrows Ezra’s spy equipment.

The Liars try to prevent Alison from sending an innocent man to jail; Hanna seeks a normal life.

Melissa reveals her knowledge of Alison’s disappearance to Spencer; Emily seeks Ezra’s help.

After years of questions and mystery surrounding the night Alison DiLaurentis disappeared, The Liars finally learn what really happened to her that September night.

Mona is messaged by ‘A’ again, Ezra is tempted to leave, and Spencer wants answers from Melissa, but gets distracted.

Daughter and dad bonding is awkward, while Ashley hopes to help Hanna by involving Detective Wilden.

Aria watches over Ezra at the hospital, while Alison and the others set a trap for “A.”

A creepy ‘hospital’ visited by Alison holds a sinister surprise, while Caleb goes along with a sting unwillingly.

All is revealed as the ultimate endgame comes to light.

Alison struggles with the death of her mother, as the Liars try to navigate through her new lie.

An uncomfortable close encounter with their nemesis awaits at least one of the tormented quartet, and a death is promised.

The Halloween before Alison vanished shows her controlling nature, and reveals other manipulative souls were also active.