Till this episode, "Dimension W" has been just your run-of-the-mill one storyline per episode model: we have Kyoma getting a mission, Mira helping him, and some characters interacting with them while they get to finish the mission, normally Loser and his daughter or Albert.
But in this episode everything changes as we enter into the big story-line the show has been teasing us from the very beginning: the big 'numbers', the 'original' coils and the accident that happened on the Easter Island. This is the big arc of the show, and it does a great job of introducing new characters while keeping the center on the ones that have already been introduced, feeding the viewer on some quite relevant back story. The pace is slow at the beginning, but after the flashback the episode gets into a frenzy mood, with lots of action, things happening non-stop and the start of a big mystery. Will the show be able to give a good answer to all the questions introduced till now? Maybe yes, maybe not, but till now it is a really funny show.