All that effort for nothing with 水の泡になる
水の泡
Literal Meaning
This expression literally translates as “to become bubbles of water”.
Usage Notes
Use it when work that seemed likely to succeed produces nothing or is suddenly undone. The phrase expresses disappointment and frustration at the wasted effort. After discovering who the murderer is, Conan explains why the murderer went after Ran. He pinpoints when Ran unknowingly discovered a vital clue. Although Fujimiya loses her memory of friends every Monday morning, she and Hase have become close enough that she feels comfortable around him when meeting him “for the first time” at school each Monday. Hase fears that progress will be lost during summer break.Examples
All that murder planning for nothing with 水の泡になる

Losing all that built-up friendship with 水の泡になる
