CAMBRIDGE — One of the key requirements for being admitted into “The Conjurors’ Club” — from ticket-buying to a group swearing-in with club pins — is a vow of secrecy about exactly what you’ve seen. So no spoilers here. It would be impossible, anyway, to be too specific about what takes place in this 80-minute live, interactive magic/theater show on Zoom. In trick after trick, four magicians will make you question "what just happened?" even as you peer ever closer at your computer screen. The sleight-of-hand maneuvers seem simply impossible and the mind-reading stunts are truly mind-blowing. At least that was the case at Sunday’s matinee performance, where “The Conjurors’ Club” host Geoff Kanick and three other magicians arrived one at a time in our small-group break-out rooms to dazzle with up-close illusions. Be prepared to be involved as information that audience members supply is worked into the live trickery to create one-of-a-kind experiences.