I'm not sure about the text on this card, we have managed to interpret it in three different ways.
First, after successfully investigating you take two horror and discover a clue and you are only permitted to investigate once per round.
Second, after successfully investigating you take two horror and discover a clue but you only take the two horror once per round and are permitted to continue to investigate for the remainder of the round finding clues as normal.
Three, after you successfully investigate you gain a clue as normal, take two horror and then gain a second clue, only taking the two horror and second clue once per round.
Any thoughts appreciated.