A guy goes to jail and is talking on the phone to his friend.

Inmate : "So what's your plan to bust me out of this Hell hole?"

Friend : "Ok. Here it is: I'm going to swallow a bunch of rope then do something stupid to get arrested."

Inmate : "I'm listening..."

Friend: "Once I get in there, I'll go to the bathroom, poop out the rope and sneak it to you. Then you tie the rope into one of those lassos you know how to make. Next time we're in the yard, we find something the rope can catch on over the fence, we toss the lasso, pull it tight, then climb to freedom!"

Inmate: "What the Hell are you talking about?"

Friend: "You know, kinda like a grappling hook."

Inmate: "No, I mean, that's really your fucking plan?!"

Friend: "Yeah, dude. I shit, you knot."

(I saw this punchline in another joke before, but I tried to think of a different setup)