Eric: "Well it can't possibly be going here.."
Me: "Put a breakpoint there."
Eric: "But it's not going there."
Eric: "How the fuck did it get there?!"'
And then his problem made sense, too. Not that we fixed it tonight, but at least we understand what's happening. Yet another case of code where they had not thought about how tab A and slot B interacted.
Twelve hour days suck.