In Milford Haven, Stu and Potts try to reunite an elderly lady with her dog after she locks herself out of her house - but they're going to have to improvise.
A newly independent Sam has a bit of an off day and starts to question if policing is really for him. Fortunately, he has moral support from his new friend and fellow rookie, Gethin.
And in Llanelli, Phil and his tutor, Burt discover that some police superstitions aren't as silly as they sound, as they try to discover why a car has been abandoned blocking a suburban street - all under the light of a full moon.
More than the usual arrests and criminal activity, Rookie Cops is a unique opportunity to look deeper into the personalities of these new officers - and to understand what drives someone to give up an established career for their dream of becoming a police officer.
At the station and at home, from their first day to their first arrest, we learn how they feel about their new careers - and about the leap of faith it took them to get here.