There is one at lv 34 called smoke and mirrors. 4 missions..1st- kill boss and 2 guards ( same map evry time )..2nd kill boss ( different map each time but just kill boss only), 3rd free captives and kill boss only ( actully very easy as the map ( same map evry time) is atlas park under statue fashion show runway, go around from left to right do boss last so you dont have to kill guards )..4th kill boss /free 2 captives ( same evry time, go to end kill boss , free 2 captive on pillers wth 2 guards each ) Once you learn the maps and patterns vry fast for 12 merits, My Blaster can do all of it in under 6 min, so 60 merits in half hour. May not be fastest but i find it very efficent.