Prior to the show, I braced for an onslaught of his gloating, but he was too busy complaining. The top critic he’d pursued had sent a cub reporter instead, leading to “four lousy sentences inked by some nobody writer.” It was these petty quibbles that firmed my choice: tonight’s finale would gain a dose of humbling twists.

With the moment here, however, I’m seized by the reality of my plan.

Cued by my introduction of the trick, the theater’s usual pair of stagehands carry out the lidless crate. Measuring three feet per side, the box smells of cedar from fresh veneers over multiple nail holes. I’m reminded of my and Charles’s exhaustive rehearsals—for an escape I’m about to upend, with a version we’ve yet to attempt. The chances of failure are raised exponentially.

Shoving away doubts, I watch to ensure the proper setup.

At center stage waits a planked table, which I designed to be sturdy yet handily disassembled for travel. Like a capital H on its side, the square tabletop and base are connected at the center by a two-foot-tall stand posing as a solid block. In actuality, it’s hollow through the middle and painted black to exaggerate its slimness.

Curiosity in the room mounts perceptibly as the stagehands place the crate on the table, creating the silhouette of a goblet. Hence the trick’s name.

“Now,” I say, “that our committee from the audience has keenly inspected the padlocks for authenticity”—the six volunteers on my left concur, each with a lock in hand—“the astute naval officer to my right will examine the crate for manipulations of any kind.”

Never resorting to the use of planted “confederates,” I handpicked the silver-haired gentleman for good reason. The more stripes on a sleeve, the less accustomed one becomes, ironically, to performing close inspections, specifically with aging eyes.

At least that’s what I’m counting on.

The stagehands tilt the box forward for a view of the interior. I knock on one sidewall at a time to convey solid construction and, more than that, to dictate the focal points. The officer nods along. I allow him several taps of his own until he reaches farther in.

“Goodness me!” I expel a remorseful sigh. “I nearly forgot. The lid too needs verified.” Aware to move on, the stagehands fetch the wooden top, plus a small stepladder and hammer from the wings. There, Charles is stripping to his underclothes for maximum mobility.

The navy man assesses the lid as I announce, “While Monsieur Bouchard rids the last of his formal garments that could potentially harbor an escape tool, I will ask the officer to lend a close eye to one additional restraint.” From my prop trunk, I hold up a straitjacket. Whispers swim among the audience; things are getting more interesting.