I want to describe here an imaginary experiment. First. take a thick walled cylinder with an open end and pour boiling water into it. The steam coming out will replace the air and then put a piston over the open end and fix it in an airtight way. But, the piston can move up and down. Now, as the steam will cool to atmospheric level and pressure inside will reduce and the piston will move down. Now, lets move the piston further to compress the steam inside with the remaining water. I want to know what will happen then? In case, if there is pure steam only inside, the steam will quickly get superheated and began to act like a gas. But, in this case, the steam will always be in contact with water here and have to be saturated and can never act like a gas. I am guessing that in such a case the steam can be compressed with far less energy consumption than pure steam. How? In this case, the steam will always be saturated and can't be superheated and therefore no need for extra effort to compress superheated steam that will act like a gas. Am I right?