Trader vs Torturer, where does the Silver go?
The Silver Gained from Trader works exactly the same as any other Gain; as Trader's text doesn't specify anything to the contrary, the Gained card goes directly to your discard pile.  This situation is explicitly mentioned on page 11 of the Hinterlands instructions:

If the card you were going to gain was not going to your discard pile, the Silver still goes to your discard pile; if the card you were going to gain did not come from the Supply, the Silver still comes from the Supply.