[osr Challenge] The Message

The Message: A Get Ready, Get Set, Go! Labyrinth Lord adventure set in the Ashford Valley.

Get Ready:
An old friend of the PCs is murdered and a note is found on the body telling them to stay out of it.

Get Set:
The PCs are in town, visiting friends and concluding deals when their old friend turns up dead. Pinned to his chest  with a dagger is a note that names the PCs and says "Stay out of it or else!"

What's baffling is the PCs are involved in anything in particular, or at least that makes any sort of sense to be  involved. With no clues, they're stymied investigating their friend's murder.

Go!:
That night in the pub, some toughs walk in and make trouble for the PCs. Any survivors (and there should be at least  one) is more scared of them than his boss, so spills the beans. One or several of the PCs have been seen around a  merchant (and his daughter) that the gang plans to rob and kidnap. The boss thought they were horning in on the  score or guarding it, and so sent a message. The rest of the gang is right now robbing the merchant at his  house/shop. The PCs are on the other side of town - will they make it in time?

Notable NPCs: The Boss; Alignment: Chaotic; Armor Class: 8; Hit Dice: 3d8; Hit Points: 20; Attacks: longsword (1d8); Save: F3;  morale: 8.

Toughs; No. Encountered: 1d6+3; Alignment: Chaotic; Armor Class: 7; Hit Dice: 1d8; Hit Points: 6, 5, 5, 4, 4, 3, 2,  2, 1; Attacks: axe or short sword (1d6), dagger (1d4); Save: NM1; morale: 6.