In chapter 12 of And Then There Were None, the unfortunate Miss Emily Brent becomes the fifth victim of the crazed murderer stalking the island. Ironically, some of the other guests believed that Emily was the murderer on account of her religious fanaticism. But the evidence doesn't lie: she's now dead as a doornail, having been injected with potassium cyanide by a hypodermic syringe.

When the other guests discover Miss Brent's dead body, Dr. Armstrong immediately identifies the presence of a syringe mark in her neck. For good measure, there's a bee buzzing around her room, which means that this murder, like all the previous ones, is related to a verse from the song “Ten Little Soldier Boys”:

Six Little Soldier Boys playing with a hive; A bumblebee stung one and then there were five.

The question now inevitably arises as to who would've had access to a hypodermic syringe. The finger of suspicion points towards Dr. Armstrong, who routinely carries around syringes as part of his job. When the doctor goes to check his medical bag, he finds that his syringe is missing. Obviously, the murderer must have stolen it.

As it turns out, Dr. Armstrong is not the only one to have a potentially deadly weapon missing. Lombard's missing a revolver, which appears to have been stolen from his drawer. This is an ominous development, to say the least. There's a murderer on the loose, and now it would appear that he has a loaded gun on him. It comes as no surprise, then, when the next victim, Justice Wargrave, is killed by a shot to the head.