Use of the trojan card

[xanderten50]

Is it possible someone could please clarify use of the trojan card?

If I defeat a monster, and someone plays trojan - does this count as a separate combat? My understanding is that since it requires the target to be collecting treasure (having defeated the enemy in question) playing trojan would require a new set of calculations and thus a fresh combat (obviously without one-shot bonuses & detractors from the previous combat).

IE: if I narrowly defeat a monster but someone plays trojan I don't have to beat the original monster *and* the trojan monster... right?