Someone is out one night, all alone, walking his dog when an alien spaceship flies over and abducts him. He finds himself lying on a table, above him is a large alien fellow explaining his current situation. The gist of it is that young alien larvae are being implanted into his intestines, where they will grow until they are strong enough to survive on their own. Eventually, they will be shat out by way of his anus, into the toilet, where they will travel through the sewers and into other humans' latrines. Then the larvae will implant themselves into many other unsuspecting humans via their poopchutes, and that is where the larvae will multiply. When their numbers are great enough, the aliens will kill half of Earth's population and enslave the survivors. The man who carried the first batch of larvae will receive the title of "Alien Ambassador of Earth", a very high and coveted position, for his service.
His payment as ambassador is a lifetime of riches and hot women.
Next comes his extremely hard ethical decision. He can either kill himself by seppuku, the ancient Japanese suicide style in which you disembowel yourself, or allow 3.3 billion people to die and another 3.3 billion to wish they were dead, all while living with all the material wealth he could ever want. If he went and tried to have the larvae surgically removed, he would be denounced as insane and receive no medical attention. There are no other possible scenarios for him to follow in order to get out of this mess.
Although he is no expert on the subject, he feels that if he were to chop out his intestines with a giant knife, it might hurt a little; seppuku does not appeal to him in the least...