Zemboy finds the book atypically boring for Christie. He believes that readers whose only exposure to her work is this novel, will be unlikely to pursue more of her books. The episodic nature of the book could have led to it being twice as long or half as long, without making any difference. The pattern of the novel is a series of dangerous encounters and failures to catch the criminals. Poirot repeatedly sets traps for the enemy. Repeatedly the enemy knows in advance and does not fall for them. On the other side, the Big Four set traps for Poirot. He evades most of them, only to find that the Four anticipated his moves as well. He does fall for some "real" traps.