You beseech an otherworldly entity for aid. The being must be known to you: a god, a demon prince, or some other being of cosmic power. That entity sends a Celestial, an Elemental, or a Fiend loyal to it to aid you, making the creature appear in an unoccupied space within range. When the creature appears, it is under no compulsion to behave a particular way. You can ask it to perform a service in exchange for payment, but it isn't obliged to do so. Payment can take a variety of forms. A task that can be measured in minutes requires a payment worth 100 GP per minute. A task measured in hours requires 1,000 GP per hour. And a task measured in days (up to 10 days) requires 10,000 GP per day. After the creature completes the task, or when the agreed-upon duration of service expires, the creature returns to its home plane after reporting back to you if possible. If you are unable to agree on a price for the creature's service, the creature immediately returns to its home plane.