Erwin Kann, once known throughout the galaxy as the Calculator, still managed to reach the Happy Islands. And their well-fed loneliness became perhaps the worst punishment. A powerful brain requires tasks, and for this you need to return to people and again cross the disastrous Sargasso swamp. But is even a Calculator capable of such a task? Many factors appear, sometimes dangerous, that do not fit into the rigid framework of formulas. And the ability to cope with tasks recedes under the threat of mortal risk... But Erwin Kann will again choose the most unexpected way out.