(you are SOUTH, dummy is EAST)
1NT = 10-13
2NT = both minors "should be a reasonable hand but not discussed in detail"
Partner leads the Jack of hearts.
Declarer plays the ace from dummy, discarding the 5 of diamonds from hand. You play the 10.
Declarer now plays a spade to the king, the 10 of spades to the queen and a third spade on which he discards another diamond.
Your partner plays the two of spades on the first round (standard count), and then plays the 7, and the 5. This is either suit preference for diamonds, or neutral (playing upwards would be slightly stronger suit preference for clubs than this is suit preference for diamonds).
You play the nine of hearts, on which declarer discards a club, partner plays a middling heart, declarer thinks for a while and plays low.
Now what?

Help

1NT 2NT P 3NT
all pass