Rookie Blue Season 4 will kick off on Thursday, May 23 at 10/9c.

The network made the announcement this afternoon, and included with it the official synopsis for the premiere, which will resume six months after Andy and Nick left for their undercover operation.

It's clear a great deal has gone down in that time. Read on for the network description:

When Andy returns to find that Sam Swarek is now a Detective and that he’s moved on, both professionally and personally, she’s going to have to figure out how to deal with it.

Meanwhile, Dov’s life gets awkward when a one-night stand with Frank’s goddaughter becomes more complicated; Chris is torn between staying at 15 Division and moving his new family back to his smaller, safer hometown; Traci is learning to work with new detective Swarek, while trying to move on from the loss of her fiancé, Jerry Barber; and although Nick and Gail have cemented their relationship, Nick can’t seem to shed the feeling that all is not right between them.”

Along with Rookie Blue, ABC will premiere another scripted program this summer.

Mistresses will be covered by TV Fanatic and star Alyssa Milano, Yunjin Kim, Rochelle Aytes and Jes Macallan. It will debut on Monday, June 3 at 10/9c.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.