Number Two

In the novel The Big Four (and the short stories making up the novel), Number Two is the designation given by the British secret service agent Mayerling for the financial muscle behind the highly secretive and powerful internation crime syndicate the Big Four. According to Mayerling, Number Two is seldom mentioned by name but is represented by the letter "S" with two lines through it. And also by another sign, two stripes and a star. To Mayerling, this first sign, is that of a dollar and suggests that he could be American.

Poirot establishes reasonably early on in the story arc that the true identity of Number Two is Abe Ryland, the "soap king" and one of the richest men in the world.