Motive Vs Opportunity

At an intimate gathering of the Tuesday Night Club, solicitor Mr Petherick recounts the perplexing case of Simon Clode-a wealthy widower shattered by the loss of his granddaughter. Consumed by grief, Clode places his trust in sinister American spiritualists, the Spraggs, eventually rewriting his will: his nieces and nephew receive a modest legacy, while the rest goes to the Spraggs-his trusted mediums.
But at Clode's deathbed signing, everything goes awry. The sealed will is opened, and it's blank. The Spraggs had every opportunity to tamper with it, but no reason. They were already poised to inherit. His relatives had every motive to nullify the will, but lacked opportunity. In classic Christie fashion, Miss Marple, drawn in by the puzzle, reveals the elegant deception: a disappearing‑ink pen planted among the servants, allowing Clode himself to overwrite his will before death, ensuring his true heirs remain protected.
This short story is a masterclass in Christie's brand of logic‑driven mystery: subtle clues, everyday objects turned weapons of intrigue, and a closed circle of suspects where nothing is as it seems.