A Little Bit Too High

My friend shared this declarer play problem to me.
Although the contract looks dangerous, an experienced declarer is still able to bring the contract home.
You may think about the declarer play before reading on.

West Pass Pass Pass

North 1  Dbl 3 NT

East 2  Pass AP

South 1  Pass 2 NT

Board 7 IMPs Both Vul

Q 10 7 4  J 8 7 3  7  K Q J 4

Trick 1

Lead  5

2nd 7

3rd 9

4th  ?

3 NT South

A 3 2  A 6  A Q 6  10 9 7 6 2

Take the lead with Q and knock out A.

RHO took the first club and returned  to knock out your A.

This contract is quite remote and the best chance is to execute a squeeze throw-in against East.

Cash all five clubs and arrive a six cards ending:

	Q 10 7  J 8 7  —  —
			K 9  —  9 4 3 2  —
	A 3 2  A 6  6  —

Above shows one of the possible holdings of East.
Depends on East's discards, you can now cash A to squeeze East.

If East discards a diamond, you can endplay him with a diamond.
Even West may get in, he does not have enough tricks to defeat you.
As long as West holds J, you can get the 9th trick in spade.

If East discards a spade, cash A now to drop K and Q is the 9th trick for the contract.

Note that you cannot duck the lead because East can return a heart to defeat you if he is 3=3=6=1 or 2=4=6=1.

The full deal:

Board 7 IMPs Both Vul	Q 10 7 4  J 8 7 3  7  K Q J 4
J 6  K 10 9 5 4  J 8 5  8 5 3			K 9 8 5  Q 2  K 10 9 4 3 2  A
	A 3 2  A 6  A Q 6  10 9 7 6 2