On January 17, Old Man Logan and Wade Wilson have to swallow their pride, put aside their differences, and come together for the greater good. And by “come together,” we mean “literally come together.”

In DEADPOOL VS. OLD MAN LOGAN #4, writer Declan Shalvey and artist Mike Henderson combine the two heroes’ bodies to create a wise-cracking mercenary with an Adamantium skeleton—also known as ‘Poolverine!

We caught up with Shalvey to hear more about this unholy combo.

Marvel.com: What do we need to know ahead of issue #4?

Declan Shalvey: We start off the issue in desperation. While trying to rescue a young mutant girl from a shadowy organization called GenForm, Deadpool and Old Man Logan have been captured. GenForm wants to weaponize the abilities of mutants, and while their target all along has been this new mutant, Maddie, they now find themselves with the fabled Weapon X—the original test subject. Admittedly, he is…a little ripe.

Marvel.com: How did ‘Poolverine come about?

Declan Shalvey: ‘Poolverine is a little nickname for Deadpool’s current state at the beginning of issue #4…if you’ve read issue #3, then you know that Deadpool has escaped from his cell in a very unconventional way.

Maddie has used her teleportation powers out of desperation. She’s always been adamant that she cannot teleport people, so Deadpool suggests she tries teleporting Adamantium. Then Wade uses Old Man Logan’s own claws to come to the rescue.

Marvel.com: Wade and Logan don’t exactly get along, so what can we expect from a team-up as unique as this?

Declan Shalvey: What I like about Deadpool and Old Man Logan is that even when they team-up, they fight. They’re the perfect match for a book like this; both their personalities force them to bump heads constantly. And, because of their abilities, they’re able to literally rip into each other and still walk away. It’s the perfect odd-couple or buddy cop scenario, but with a lot more severed limbs.

Marvel.com: What do you see as their greatest strengths? 

Declan Shalvey: Well, they both have healing factors. They can both take a lot of punishment—from their enemies and from each other! As characters though, while they have their flaws, they both want to do the right thing. Their motivations for helping Maddie may be petty, but they do want to help her. They’ve both lost young girls in their lives—Deadpool missed his daughter’s infancy; Old Man Logan’s young daughter was murdered along with the rest of his family. So they’ve both endured emotional tragedy and physical torture. Both changed, but have come out the other side. They’d never admit it, but they have a lot in common.

Marvel.com: What are their weaknesses? 

Declan Shalvey: Frankly, Deadpool is immature, Old Man Logan is short-tempered, and they’re both as stubborn as each other. It makes for great character work, but it makes it hard for them to achieve their goals.

Marvel.com: How will those factors play into their quest to save Maddie?

Declan Shalvey: The main obstacle for the last few issues has been getting Maddie on board while fending off the GenForm organization. In issue #4, however, we reach a crossroads of sorts, with both Deadpool and Old Man Logan choosing very different tactics to solve the problem.

After the events of this issue, we’re going to see Deadpool and Old Man Logan really bust heads over what to do with Maddie. Their concerns will have proven to be valid, as we also learn a shocking secret—something that will change the entire outcome of this story.

Marvel.com: Describe your favorite scene in issue #4!

Declan Shalvey: Hmm…There’s a double page spread in this issue that I love. And the following page in that scene is a nine panel grid, all of Logan cutting loose. I felt so frustrated writing it because I wished I was drawing it. And, as expected, Mike Henderson killed the scene.

Marvel.com: How has Mike Henderson helped realize your vision?

Declan Shalvey: Issue #4 is where Mike gets to really cut loose, and it’s a joy to behold. We really deliver on the “vs.” premise—we’ve been building to this climax since we started. I’m so delighted with how this limited series has turned out, and I can’t wait for everyone to see what happens next.

Dig your claws into DEADPOOL VS OLD MAN LOGAN #4, by Declan Shalvey and artist Mike Henderson, on January 17!