[whereagles]

Well, if I were to bid 3♦ I wouldn't pull pard's 3NT. Masterminds are to be done with strong hands, not marginal hands with weakish suits.

Which is why I think 3♦ is optimistic. If my diams were good, i.e. topped by the ace, then 3♦ would be more reasonable. Heck, I might even bid that

[Codo]

Excellent problem.

I agree with Justin et al that this hand is surely strong enough for 3 ♦.

But as others pointed out, some unusual bidding had been done so far:
Pd doubled a suit for take out where you have a chicane.
RHO did not raise despite having some clubs.

So what are the possible hands for pd?
4405? 4414? 5413? 4513?
I think one thing is sure: He has at most 2 diamonds, or he did double with 4333 or 3433. In any case, 3 NT is not out goal- it could be right but it seldom is.
If he has fit, we belong in 5 Diamond, else in a major.

So I would bid 2 ♦ and take the risk to play in 2 ♦ if this is passed out but have a much easier way to the right strain if pd has no fit.