manfuzu,
"Lay Down Misere" is a card term from the game "500".
(Misere: French for "poor" or "poverty")
It means that you have an unbeatable low hand (so good that you can just "lay it down" for all the players to see, and save them the trouble of playing on as you already have the winning hand)
In general parlance used to indicate "an absolute certainty"
(which SSN is not!)
sasa