This one is so ridiculous, it's going to take a bit of explaining. Okay, so DC's first attempt at tidying up their increasingly tangled multiverse was a 1985 miniseries called Crisis On Infinite Earths, which centred around an eons-old battle between two cosmically powerful foes finally coming to an end. Those foes were the Monitor and the Anti-Monitor, two immortal and celestial beings who has opposing goals: the former, to collate all knowledge in the known and unknown universes; the latter, to destroy all said universes. You can see where the disagreements began. From there it gets a lot more complicated because, well, comic books. Once all that got settled the Monitor we thought we knew disappeared. He was later replaced with a whole race of Monitors, each of whom was dedicated to protecting one of the many alternate Earths in the multiverse, which came under threat in recent storyline Countdown. That was all down to two radically opposing viewpoints in the Monitors arguing about how the multiverse should be maintained, suggesting "Multiversal Anomalies" (people who have hopped from world to world) should be dealt with in a somewhat harsh manner. Then they all got wiped out during Final Crisis anyway. Woops. So what now? According to The Multiversity map they still have a whole quadrant to themselves, existing outside of both the alternate Earths and the ring of gods and afterlives, but surely there isn't anyone left to do the policing? Final Crisis saw a Monitor being reborn in human form, and Nix Uotan has since been seen in the preview for Multiversity #1. So if that comic - and the DC multiverse in general - didn't seem ridiculously brilliant and brilliantly ridiculous as it is, there's a good chance it now features undercover cosmic beings protecting the very fabric of reality whilst pretending to be regular people. Yep.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/