You need to choose and declare when you flip. If you're wrong you miss the effect of the declared upgrade, but you can pick up using the other upgrade because the top card isn't scrapped. If you got it right then you have a new top card, and can use the other upgrade effect. So X attacks, say "I'm using Anticipation" flip top. if it's an action play it and then use metal detector on the next top card. if it's an upgrade then don't play it, put it back on top and use metal detector to play it.