Reveal two cards (certain effects may increase or decrease this number) from the Encounter Deck. Choose one of these cards, putting the other(s) in the Encounter discard pile. Now you must choose whether to resolve the encounter or to rest.
Once you have carried out your Rest or Encounter (or were forced to do nothing), move the token on your Time Tracker according to the Time Value of the chosen Encounter Card — this represents how much Time you spent — and then put the card in the discard pile. If this causes your Time Tracker to reach “0”, your preparations took too long and the monster ambushed you — proceed immediately to the Ambush Step of the Combat Phase.
Even if your Time gets to “0”, you receive the full benefit of the card you used during Exploration.