The Three Dog Detective Agency of Chula Vista has traveled far and wide in their fight against evil. This time, however, they go where no dogs have ever gone before, through space and time and into alternate timelines. To battle the evil of Lord Cerberus, a foe unlike any other, they must ally themselves with the intrepid Dogs of S.T.E.A.M. Together, they fight not for the fate of one world, but several.