Quiz night: Can Mac save his marriage and why does Brian hate Michelle.

Michelle battles her ex for what she loves most; Mac takes on his nemesis; Emma breaks her losing streak.

Brian has the chance to recapture his past; Mac goes head to head with family.

A new team member sets a cat among pigeons; Emma's latest romance is a loaded gun when it comes to Brian.

New adversaries leads Brian into dangerous liaisons; Michelle finds out that war can have its upside.

Mac fears for Catherine's mom; Brian wants to get rid of an interloper.