The Left Hand of the Magician - S1-E5
Plot hole: Luca draws the sketches of a magic trick, but they contain a fatal flaw that would kill whoever is doing it. He is hospitalized so he takes no part in the setup, so there is basically no chance that the flaw would go undetected. Other people are building the stage and device and they'd do at least a couple of tests before debuting a death defying stunt with live arrows and fire during the show.