Sour
Stuck
Roof
Tick
Helmet

Y'all have no idea how stumped I was on this one. Legit, you'll see this one is two days late, I finally got the idea on the 16th. Anyway, here's the line of thinking for this one, if anyone is wondering: This guy, he's in a rather sour mood. So he stuck a gun to the roof of his mouth, ready to blow his brain out of his skull (his helmet, if you would). He pulled the trigger and heard a tick, signifying that the gun either wasn't loaded or that the bullet in it was a dud.

Look, clearly "helmet" is the weak link here, all of them have had weak links. Knot, pick, helmet, next ones are gonna be fuzzy and patch. What if I did a bonus round where I tried to mash up all the weak links? Seems easy enough.