All that murder planning for nothing with 水の泡になる
Idiom Explanation: All that effort for nothing with 水の泡になる

After discovering who the murderer is, Conan explains why the murderer went after Ran. He pinpoints when Ran unknowingly discovered a vital clue.
- コナン:
- 「あの時、蘭
( の事( 気( にもとめてなかったが、もし思( い出( されたらせっかく組( み立( てたこの殺人( 計画( がすべて水( の泡( になる…」- “Ran didn't think anything of it at the time, but if she remembered it, all the murderous plans he worked so hard on putting together would go up in smoke.”
Key Points
水
( の泡( になる = to come to nothingThis idiom means all the effort would be wasted.
In the scene, the culprit’s carefully built murder plan would collapse if Ran remembered the clue.
せっかく highlights the effort invested
せっかく組
( み立( てた means “carefully” or “with effort put together”.That makes 水
( の泡( になる feel more tragic or frustrating.
もし思
( い出( されたら sets the conditionThe idea is “if she were to remember it”.
Everything after that clause is the consequence the culprit wanted to avoid.
See Also
- Kanji: Counting and planning with 計
- Kanji: People and persons with 人