Diminishing Returns ventures into uncharted waters in its first episode since the loss of Calvin. In his place, this week, is Judey Bignell and the one-third-new trio explore 2008's inexplicable smash hit Mammia Mia! With Mamma Mia: Here We Go Again! soon upon us, Calvin felt we had to cover the jukebox musical behemoth, then he buggered off so that he wouldn't have to sit through it.