[Title: HOT AND COLD] [Verse] Heat flows down from hot to cold Through a cycle, controlled and slow Take from hot, release to cold Do some work along the flow [Chorus] Between hot and cold That is all that matters No engine can do better Than this limit set forever [Verse] Run it forward, run it back Reversible along the track No extra loss, no hidden cost Nothing gained and nothing lost [Chorus] Between hot and cold That is all that matters No engine can do better Than this limit set forever [Bridge] One minus cold over hot Sets the upper line No total entropy change In the ideal design [Outro] Hot and cold define the way Every engine must obey