After last month’s future-set spoiler issue, this week’s BATMAN #29 marks the return of “Zero Year” and the conclusion of the storyline’s second chapter, “Dark City.” If you’ve been reading, you know that the still pretty untested Dark Knight has been dealing with no shortage of problems, including a city-wide blackout, a major storm and plenty of trouble from the Gotham City Police Department. However, most disturbing of all may be the grotesquely malformed corpses that have been popping up around the city—the gruesome calling card of a previously unheard of villain known as Doctor Death.

There’s a lot we don’t know about Doctor Death yet, not the least is why he’d inject himself with the same bone-growing serum he uses to kill his victims and how he manages to eat anything with those overgrown choppers of his. (Seriously, how does he do it? We’re not even sure how he manages to swallow water considering he seems to have no lips.) But since there’s not really any point in speculating about what we don’t know—particularly when issue #29 is likely to bring us some of the answers—let’s break down some of the things we do know about this strange new member of Batman’s rogues gallery.

He’s a former Wayne Enterprises employee.

Doctor Death’s real name is Dr. Karl Helfern, a former Wayne Enterprises employee who specialized in nanomedicine and whose work sought to alter bones to make them reactive. The idea was to treat bones at the cellular level so that they’d harden upon impact, making fractures a thing of the past. Helfern accomplished this through a serum—a formula that’s patent is held by…you guessed it, Wayne Enterprises. Fortunately, so far the only people to link Doctor Death to Wayne’s company seem to be Bruce Wayne and Lucius Fox, but you have to wonder how long that will last. In fact, it’s entirely possible that the GCPD knows. After all, we know Doctor Death set Batman up to take the fall at his most recent murder scene, something that proved near fatal for the Dark Knight.

Along with injecting others, he’s also used the formula on himself.

One look at Doctor Death and this one’s pretty clear. The dude’s obviously not one for keeping a low profile. But aside from the grotesque appearance, consider the ramifications of this. His bones, giant and distorted as they may be, are also pretty much unbreakable. Batman is a hero who uses incapacitation to defeat his enemies, frequently breaking bones to put his opponents down. It’s part of his strategy. But that’s out of the equation when dealing with Helfern.

While this does mean Batman’s free to fight with less restraint than usual, it doesn’t seem like taking the gloves off makes much of a difference. We’ve seen Doctor Death take a lead pipe to the arm, a gunshot to the back and even seemingly get pulled into a jet engine and walk away from all of it. He may not be immortal, but clearly brute strength is not going to work on this guy. Plus, there’s more to this bone-based ability than just defense. Helfern knows just where to hit a bone to break it, and with a skeleton that hardens upon impact, getting struck by the guy—or finding your head within his giant hand, as Bruce experiences in BATMAN #26—is going to hurt. Badly.

Let’s face it, not only did that fight go poorly for Bruce and Lucius, it was one of the most disturbing confrontations in Snyder’s Batman so far. And that’s saying something.

He’s working with the Riddler.

We’ve known the Riddler has something in store for Gotham, but in BATMAN #27, we learned that Doctor Death has actually been helping him achieve it. Bruce had assumed that the two villains were working independently from each other and possessed differing motives, but that was wrong. We don’t yet know exactly what the two are brewing. Issue #27 ends with some cryptic warning about a Doomsday Machine, but this would seem to be a villainous team-up that makes horrific sense. While the Riddler may be brilliant, he’s never been a physical villain. He could never go hand-to-hand with Batman, but Doctor Death can.

Of course, Batman was in plenty of trouble when we last left “Zero Year.” Bruce will need to escape the trap the Riddler set for him at Doctor Death’s lair before he stands a chance of squaring off against either of them. And if he does get that chance, Bruce is almost certainly going to need to cut out the hard-headedness and accept some help from Alfred or Detective Gordon. Going at these two alone has not worked out well for Batman, and with a whole new chapter of “Zero Year” awaiting us just around the corner, it’s safe to say that the Dark Knight and the darkened city of Gotham are nowhere near out of the woods.

So what do you think these guys are up to? What's with all of the flashbacks we've been seeing that seem to tie in with the Riddler's plan? And do you think he'll actually succeed? For more on "Zero Year," be sure to catch today's all new episode of DC All Access.