Limit 1 per deck. As an additional cost to play this asset, place 1 resource on 4 different locations, as leylines.

After you successfully investigate a location with a leyline, exhaust this asset: Move that leyline onto this asset. Then, if there are 4 leylines on it, discard it, take its leylines as resources, and record in your Campaign Log that "you have identified the gateway."