Conan figures out the object was the real Stradivarius that lured the grandmother to fall to her death. He reveals the culprit to be Kyousuke. Kyousuke reveals that the Stradivarius was originally from his family. One day, the Kyousuke's father was asked by his brother, Choichirou, to burrow the Stradivarius. He then attempts to to send back a replica to Kyousuke's father, but was found out. In an argument, Kyousuke's father falls down the stairs. Choichirou orders his family to not call the ambulance and to staged it as robbery. This is the cause of Kyousuke's father's death. As Kyousuke is taken away, Conan asks him the tune of a song from the cellphone numbers and finds out the Boss of the Black Organization's number is the song of "The Seven Children".
Wohl niemand sonst als Conan hätte diesen verwickelten Fall aufklären können. Um den anderen seine Erkenntnisse mitzuteilen bedient er sich wieder einmal der Stimme des schlafenden Kogoro Mori.
Conan riesce a capire chi è il colpevole degli omicidi
Conan resuelve el caso, y finalmente le pregunta a Haga que notas son 0858, y si conoce una canción que comience con esas notas. Y Haga silba la canción "Los siete niños".
En Conan ha deduït que els suposats accidents de casa de la Hasuki en realitat són assassinats en sèrie planejats amb molta intel·ligència. Però... i el mòbil dels crims? Doncs de vegades és una mica difícil trobar el mòbil d'un crim, sobretot si es remunta a coses que van passar fa més de trenta anys. Però segur que un stradivarius falsificat i un accident desafortunat hi tenen alguna cosa a veure...
