Tensions are at an all-time high with Jake's older brother Christian back in town and the Doyles are on a case involving Walter's soon-to-be brother-in-law.

After getting a call from his brother Christian, Jake must help prove him innocent in a shady murder case. Meanwhile health issues creep up on Mal and Des along with Tinny take on a case by themselves.

When a member of the Doyle clan is in danger from both the police and a killer, the family comes together to stay safe.

It's matrimony -- Doyle style -- as Jake and Mal are tasked with finding the person responsible for sabotaging an upcoming wedding; Mal and Rose fix a bump in the road in their relationship as Jake and Allison hit a stride in theirs; Des comes to Tinny's rescue but ends up exploding her plans in the process.

When an old Doyle family friend accidentally goes missing at sea, the Doyles are hired by his daughter to find out what really happened; Jake is forced to bail out Christian and picks up another line of business and a pile of new debt.

Jake and Mal are called to check into some death threats that have been made to a respected psychiatrist; an old "friend" from the past shows up and makes an interesting proposition to the Doyles; after Leslie's close call, Jake and Leslie find themselves struggling a little in their new romantic relationships.

Jake buys an expensive gift for Allison only to have it stolen by a thief; The Mayor finds himself in a compromising position and asks for Jake's help and his silence; Mal has trouble telling a lie to his kids; Leslie thinks she's being followed.

The Doyles are hired by a real estate agent to investigate a series of strange occurrences at the site of her controversial housing development; Leslie uncovers some suspicious facts about the Mayor; the tension between Jake and the Mayor hits a high point; Allison makes Jake a serious proposition.

When Tinny and Des are snatched from the safety of the Doyle home in broad daylight, Jake is forced to confront a dangerous man from his past (Paul Gross) to get them back; Leslie loses something else very precious to her; Jake makes a decision about his future with Allison.

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 are hired to recover a missing item belonging to a beautiful client; Nikki asks Jake a favour he wants nothing to do with; Tinny enlists Des in keeping a secret.

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.

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.

Leslie offers to help Jake and the Doyles.

Jake searches for evidence to prove his innocence; Mal and Rose question Doyle's return.

Jake must solve a puzzling case; Ned Bishop jeopardizes an important day; Leslie's past actions come back to haunt her.