Reality TV host and real estate magnate Donald Trump is determined to own this year’s October surprise, promising to drop a “bombshell” about President Barack Obama early Wednesday.

Trump, who has become the de facto head of the birther movement, has remained tight-lipped about what the revelation might be. But that hasn’t stopped bookmakers from speculating about his purportedly damaging intel. Overseas betting house Paddy Power, for instance, is offering 2-to-5 odds Trump will declare that POTUS is not an American citizen. Our favorite wager: 250 to 1 that Obama gets outed as an extraterrestrial.

The duo has fought off and on throughout the Republican primary, a sublimely ridiculous feud Slate has summarized in this brilliant “Mortal Kombat” spoof: