The eponymous plot is a tricky one to use, at best. If your opponent is going first, then you just need to defend a int challenge, and the plot has paid for itself. However, with an initiative of 2, the more oft encountered situation is going first, which means haiving to attack in an int challenge first. This makes it much easier for your opponents to win an int on attack back, and then do the rest of their challenges.
This is however, good out of rains, because if you can trigger this on defence with them going first you have just won the challenges round. However, this is still rather difficult, due to the 5+ or more requirement on rains.