The final ugly board of the nightmare set was the ugliest of all.  I pick up in 4th, unfavorable:

AQ87 / Q6532 / - / KQT7

Jeff opens 1 Diamond, I bid 1 Heart, he bids 2NT and it's up to me.

We play that 3 Clubs relays to 3 Diamonds (Wolff signoff) and that 3 Diamonds is artificial and game forcing here. 

Over my 3 Diamonds, Jeff bids 3 Hearts.

What now?

I can bid 6 Hearts, but that's an awfully gross suit to want to play in a 5-3 fit.  We could be cold for 7, we could be down in 6.  Is there a way to proceed that lets us make an intelligent decision?

I continued with 3 Spades.  We're in a game forcing auction, if he wants to take it as a cue bid, I have the ace, if he takes it as a suit, I have spades.

Jeff now bids 4 Diamonds.

Yuck.  Not a big surprise, but it sounds like he's missing the ace of clubs or he's trying to show me a 5 card diamond suit.  What now?

Well, if Jeff is cuebidding, he can't have the ace of clubs, so if I bid 5 Clubs, he will know to focus on his hearts to decide whether to bid 6 (obviously if he's off the ace of clubs, I don't want to be in 6 off the ace or king of hearts.)

Conversely, if Jeff is showing a suit, I can bid clubs naturally, because we haven't found a fit.

Brilliant!  Either way Jeff has to get this right.  Either we're cuebidding and he'll bid it because his hearts are good, or we're bidding naturally and by shaping out as 5-4-4, he'll know how much wasteage in diamonds he has.

Over my 5 Clubs, Jeff bid 6 Clubs.

Well, if we're on the same page, he's gotta be specifically 2-3-4-4 without the ace of clubs, so we've arrived.  I passed.

We were not on the same page.  We were reading different books.  In different languages.

Jeff held:

KJ / A94 / AQ986 / A53

Our opponents were in 6 Hearts doubled, which wrapped when the Heart K was onside tripleton.  6 Clubs is an interesting contract, but had no play (J9xx of clubs offside.)