I know it's been ten days since release, but I finally got to read Immortal Hulk #4 today. I am really loving this series. It's a slow burn, taking its time to set up the (new) rules of the world in which it's set and to build the personalities of the players involved. There's also a really nice mystery here: What changed? Sure, you could argue that it was always this way for the Hulk. In fact, in issue 1 or 2, the book essentially tells us that, that the green door has always been there to let the Hulk back (and, it seems, bring Banner back with him). But with Walter and Sasquatch, this implies that something about the rules of the world changed. The green door is not unique to the Hulk.
And it sure seems that Tanaraq is the one that opens the door for Walter...
(And Bennet's art really shines on that final splash page of Sasquatch!)