Unusual Phenomenon Sighted in Arkham! is a mythos card. It first appeared in the Kingsport Horror expansion.
Mythos Type: Headline
Gate Opens: Unvisited Isle
Clue Appears At: *Hibb's Roadhouse
Mythos Ability: The first player must choose one inactive rift (if there are any). That rift's track immediately fills up and the rift opens.