Jake is forced to team up with a former partner; Leslie must step up when a colleague is attacked.

Jake and Leslie fight for their lives; the Doyle's get help from an unexpected ally, but they must find evidence to clear Jake of murder.

Jake faces the consequences of his actions; Sloan makes an important decision about her future.

Jake and Mal chase after a mysterious and troublesome woman.

Sergeant Jake Doyle is assigned to protect a mob informant but when a mysterious group of men impede him, Jake finds the tables turned - himself the target of a manhunt.

The Doyles struggle to prove Mal's innocence when he's accused of murder, but end up digging a deeper hole; Kathleen gets some brotherly help with the George situation; Tinny discovers the identity of her father.

With Tinny abducted at gunpoint by Maurice Becker, Jake and Crocker have no choice but to work together to get her back. While being held captive, Tinny attempts to get into Becker's head.

Jake crosses paths with a hot-headed cop.

Jake traces a sketchy money trail; Leslie faces some conditions upon her return to work.

Jake and Mal are given no choice but to help an escaped convict prove his innocence, and they get a glimpse of the drug trade in the city in the bargain. Tinny's curiosity about her father grows. Jake finds out why Leslie's been off the radar.

Jake's worst fears are realized upon discovery that Leslie has gone missing while working her dangerous undercover assignment, and now he's determined to find her at all costs. Meanwhile, an unlikely and suspicious client enlists Des's PI services.

The Doyles are hot on the trail of an international art thief; Constable Hayward makes a grave mistake with career-impacting implications; Leslie struggles as she deals with an important family issue.

The city is thrown into chaos when a prison break floods the streets with escaped cons, and a threat against Tinny makes it extremely personal for Jake; Unfazed by the warnings from her uncle and grandfather, Tinny oversees a police transport of seized guns and drugs.

Leslie's informant is murdered.

Jake must solve a case while facing the facts about Leslie; the Doyle's try to adjust.

The extended Doyle family shows up on the doorstep unannounced and in huge trouble, leaving Jake and Mal to tangle with some formidable gangsters from across the pond.

When a crazed bomber takes over the police station, it's up to Jake to try and diffuse the situation from the inside before the hostage crisis can turn fatal; Trapped outside, Leslie leads the RNC command post with Jake's life hanging in the balance.

Jake's location is uncovered in the Season 5 premiere. Later, Tinny oversteps her bounds.

An old nemesis interferes as Jake pursues a criminal.

Jake's murder charge takes center stage; Leslie's job is on the line; Des is in the wrong place at the wrong time; Tinny is torn between her family and her job; the Doyle's have just 48 hours to solve a case.

A wrongfully convicted murderer gets out of prison and offers the Doyles a generous payday if they find the real killer; Jake finds out the truth about Nikki’s pregnancy.

A grieving widow hires the Doyles to find out why her husband left a generous sum of money in his will to a woman she’s never heard of. Rose continues to battle with Martin over their divorce while Mal formulates a plan to get Poole out of their lives for good; and Leslie and Jake hit a comfortable stride as friends and colleagues - just as his divorce from Nikki becomes final.

Jake and Mal investigate a hit-and-run and encounter a slippery criminal couple; Rose has a run-in with familiar ghosts from her past; Des discovers that Tinny's trip to London didn't go as expected. Guest star: Shannon Tweed

It's a trip down memory lane as the Doyles investigate the murder of an old client. But when the body count rises, Jake starts to question the whole case. Rose gets in hot water with the police and Des's budding romance with med student Chandra begins to rub Tinny the wrong way.

Jake is hired to retrieve a priceless violin from a familiar con artist; Mal continues to dig into the death of his former partner; Kathleen is roped into another of George’s schemes.