Home Body Clue - chp9

So who's doing what here? Let's play-by-play, keeping an eye on those bits.

White and Mustard are out of the room when Body explains the value of the bits. This doesn't exclude either of them from being the thief, but we'll keep it in mind.

Peacock is the recipient of the first trick, after which White returns.

All present players are the recipient of the second trick; Plum and Scarlet pick the middle card, while White and Peacock choose left. After the end of the trick, Mustard now rejoins the party, and Scarlet leaves for some apples and a knife.

Plum is the recipient of the third trick, introducing Candlestick, exeunt Plum for ice. Nopony acknowledges Mustard's confusion over Green's 'magic'.

The fourth trick, bit juggling, frees the bits from their case. (Currently present are White, Mustard, and Peacock).

Trick two part two sees the return of Scarlet, who brings the apples and the knife. Green puts the bits back down on the table, and here's a trick - it was mentioned earlier that to the untrained eye, the five bits look completely ordinary. Scarlet has no way of knowing that these are Body's bits. Same goes for Plum, who's still out of the room.

In fact, the only three who do know that they're Body's bits are White, Mustard and Peacock. Four, if you count Green.

Scarlet's getting pretty mad about all this. Peacock leaves for more cards, and Plum re-enters; his hoof still hurts.

Then cue rainboom. The thief strikes Green over the head with the Candlestick and steals the bits, then joins the others at the window to look.

Peacock now re-enters, and accuses... who?

All of the card stuff is just distraction, just like in real stage magic. We're only interested in those bits.

PEACOCK is in the clear. She was out of the room when it happened.
GREEN was assaulted. Could he have hit himself with the Candlestick to steal the bits? Unlikely. He had his hooves full with the cards.
SCARLET was pretty mad about the card tricks, but she was out of the room when the bits were liberated from Body's case as mentioned above. Why would she steal them? It's just five bits, after all.
PLUM was also out of the room when the bits came out. He could have used his magic to thump Green despite his aching hoof, but again, he has no way of knowing that they're actually Body's bits.
WHITE was out of the room when Body explained the value of the bits.
MUSTARD was also out of the room when Body valued them.

So... wait. That clears everybody! Stage magic is afoot. Let's revisit everyone, step by step.

First, the valuing. Could Mustard or White have listened at the door to hear the value? Well, Mustard couldn't have. He left first, and if he had stayed, White would have run into him. White? She actually returned first. Maybe she could have listened at the door for a moment.
Plum, Scarlet, Peacock and Green are all otherwise present.

The liberation of the bits. Scarlet is out of the room, and comes back with the apples and a knife, and she's determined to find the Princess, so she wouldn't have listened. Plum muttered something about leaving to get ice - but didn't actually come back with any.
Mustard, White, Peacock and Green are all otherwise present.

The thumping. Her absence proves Peacock's innocence, and she points out the thief besides. Otherwise, everyone is present. Green was the victim - but he was flipping the cards about with one hoof only.

Realistically, we're looking at two ponies - Plum and Green.

Of those two, only Green was present to hear the value of the bits, and know that they were out of the case; he freed them, after all. It's possible that he used some sleight of hoof to conceal the bits then drop the Candlestick on his head.

But assuming that he didn't do it himself, Plum might have a sore hoof, but he's a unicorn, he's got magic, and he's the only one who left the room and didn't come back with what they were looking for. Mustard went for a towel, and got one. White went for a mop, and brought a bucket. Scarlet went for apples and a knife, and got them. Plum went for ice, and didn't come back with it. (However, Scarlet rushed in almost immediately after the bits came out - she would have noticed him standing there).

Where does that leave us? Green. The Princess in the apple trick would have required preparation, he might have intended to do some card tricks anyway, but if we look at everything together...

He heard how much the bits were worth.
He put the Candlestick on the table.
He freed the bits from the case.

It's a tough one, but I'm going to do something risky and say that
It was GREEN, with the CANDLESTICK, in the BILLIARD ROOM.