Rule Clarification: If you discard Ice Pick for additional damage or clue...
- Yorick can play just discarded Ice Pick by investigator's ability.
- Resourceful can return just discarded Ice Pick in hand.
- Scavenging can not return just discarded Ice Pick in hand.
The reason of above things:
Yorick: Ice Pick is discarded to deal additional damage. Thus, Ice Pick is discarded before the damage is dealt. Therefore, the enemy is defeated after Ice Pick is discarded.
Resourceful: Both discarding Ice Pick and returing card by Resourceful have same resolving time (ST7 -- if you succeed). Hence, you can choose which one is first. You can resolve discarding Ice Pick -> discovering clues -> returning card from discard pile.
Scavenging: "after you succeed" (scavenging) is ST6, and "if you succeed" (ice pick) is ST7. Thus, you should trigger Scavenging before you discard Ice Pick. It's the same that TATA + Take Heart doesn't work.