Let's start with an opening lead problem:

In 2nd seat you pick up:

T765 Q2 86432 72

RHO bids 1 Diamond and the bidding proceeds:

1 Diamond - P - 1 Heart - Dbl
1 Spade - P - 2 Clubs (4SF) - P
3 Hearts - P - 3 Spades - P
4 Hearts - P - 4NT - P
5 Hearts - P - 6 Spades - Dbl
6NT - P - P - Dbl
P - P - P

Prithee, what stabbeth thou? (and why, preferably.)

Edit: David Clement was kind enough to point out that 'YOU' are not on lead, your partner is.  So if you led anything at all, you have the same annoying tendency I do (to subconsciously ignore artificial bids when figuring out who is declarer on a given hand.)

If you led anything but a club, you're writing a 4 digit negative number on your card (unless you're one of those cool kids who leaves off the last zero, then it's a 3 digit negative number.)

But in point of fact, the actual auction didn't end thusly.  After the double of 6N, it continued P - P - 7H - P - P - X - P - P - P.

The one diamond opener held:

- / AKJ9 / QJ975 / J943

The one heart responder held:

AKJ4 / 87543 / K / AT6

Assign blame.