Here's a short story:

Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be used. The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle. In the cycle, water is heated and transforms into steam within a boiler operating at a high pressure. When expanded through pistons or turbines, mechanical work is done. The reduced-pressure steam is then condensed and pumped back into the boiler. 

The first commercially successful true engine, in that it could generate power and transmit it to a machine, was the atmospheric engine, invented by Thomas Newcomen around 1712. It was an improvement over Savery's steam pump, using a piston as proposed by Papin. Newcomen's engine was relatively inefficient, and in most cases was used for pumping water. It worked by creating a partial vacuum by condensing steam under a piston within a cylinder. It was employed for draining mine workings at depths hitherto impossible, and also for providing a reusable water supply for driving waterwheels at factories sited away from a suitable "head". Water that had passed over the wheel was pumped back up into a storage reservoir above the wheel. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: What is a true engine?
Guess: atmospheric engine

Question: What does it mean to be a "true engine"?
Guess: it could generate power and transmit it to a machine

Question: Who made the first successful one?
Guess: Thomas Newcomen

Question: Was that in the 19th century?
Guess: no

Question: When?
Guess: around 1712

Question: Was it any better than the previous steam pump?
Guess: yes

Question: What made it better?
Guess: used a piston

Question: Whose idea was that?
Guess: Papin

Question: What was this engine used for mostly?
Guess: pumping water

Question: Where was it used?
Guess: mine workings

Question: Anywhere else?
Guess: factories

Question: Was it an efficient engine?
Guess: no

Question: What kind of engine would a steam engine be classified as?
Guess: external combustion engines

Question: Is the fluid in the same compartment as the combustible ingredients?
Guess: no

Question: Could a steam engine work with nuclear power?
Guess: yes

Question: What about energy from the sun?
Guess: yes

Question: How about from the moon?
Guess: unknown

Question: What is the perfect thermodynamic cycle called?
Guess: Rankine cycle

Now answer the following question in the same format.

Question: What happens to the water in this cycle?

water is heated