A diva of a Doberman, a police K9 with a fear of water, an American Bully underdog, an avenging Rottweiler and an explosives detection dog all put their best paw forward but only one will stay the course and take home the coveted Top Dog title and a spot in the grand finale.

An invasive mussel sniffing working dog will take on four underdogs: a Pitbull with a Hollywood bloodline, a dock diving super mutt, an ex-narcotics detection black lab and an all-female team ready to show the boys who's boss. In the Dog House a handler's fear of heights threatens to DQ a team.