Taking a step back, here's a quick overview of how v10 of the game, the latest version, works.
Lost Adventures is an Indiana Jones-themed relic hunt, and like a good Indiana Jones movie, the action is divided into two principal phases. In the first, the players traipse around the globe, trying to gain information about the whereabouts of a lost artifact, which is hidden in a lost temple somewhere. In the second, the players discover and enter the temple, and try to be the first to traverse its twists and turns (and traps) to locate the lost artifact in the temple.
Along the way, the players will be harried by the Enemy, who seek the artifact for their own nefarious purposes. In the first phase, as players travel around the board, Enemy Operatives (pawns) will chase them from city to city, disrupting the players' ability to acquire information. Inside the temple, the Operatives race the players to the artifact, or try to steal it from the players if possible. The enemy's overall progress is measured on a track, and when it reaches the end, the game ends and all players lose.
The main "innovation" in the game is its information system. Simply put, the game "knows" what city the temple is in, and it "knows" where in the temple the artifact is hidden. There are three solution categories that contain hidden solution information, and each has a corresponding deck of solution cards, one of which is chosen from each category at the start of the game. There are three levels of clues for each, and players gain access to these by visiting "theme cards", representing people and items that provide information. So, for example, you go see Henry Jones if you want information about the temple's traps; you seek the Knight's Shield if you want to know where to find the temple, etc.
To access a theme card, you have to go to the city it resides in and face an Encounter card, which includes a challenge and, possibly, moves an enemy Operative to the city as well. If you fail the challenge, the Operative gets to use his special ability, but if you pass you get to interview the theme card, which consists of checking off boxes on your notepad. Every 3 boxes you check in a category unlocks the next level of clue in that category.
The turn mechanic is simple and clean. You resupply (draw action cards), take up to 4 actions, and then draw event chips from a cup and resolve them. This turn structure persists across both phases, but the details of the available actions change a bit inside or outside the temple.