Backfill

When you deploy it, choose 5 cards in your scrapyard and shuffle them into your hold; with fewer than 5 there, you can't deploy it. Shuffling them isn't salvaging, so it doesn't count for the Sapper engine (306.5, 603.8).

Choose how many, from 0 to 2, then draw that many (801.1a).

In your own watch, while this card is in your scrapyard, you may pay this to return it to your hand. No one can react, and there is no limit per turn (802.2d).