Three card promo pack from Looney Labs that can be used with both Chrononauts and Early American Chononauts. This trio of Chrononauts cards can be added to either version of the game. Each represents a sarsen stone that was removed from Stonehenge during the Dark Ages and lost to history. Each is slightly different; collect all 3 and you can recreate a trilithon. Doing so is a bonus Mission that becomes an alternate way to win. But you can also discard a Megalith in conjunction with Sell an Artifact for a whopping 3 card gain.