The film starts with Conan having a dream. He is sorting and hears some noise but doesn't see anybody. Gin and Vodka suddenly appear. Gin has come to kill Shinichi.

The next scene shows the Detective Boys as they are catching beetles with Agasa. Agasa's new invention lifts Genta to the top of a tree where he, along with Ayumi, Mitsuhiko, and Conan, find a beetle with its wings taped together.

The opening also shows a flashback regarding the chat between Conan and Vermouth in her car and the phone number of "the boss".

A man driving down a hillside road suddenly realizes that his brakes don't work. Traveling at a high speed, he crashes into a toll station. He dies but he leaves a mysterious dying message: "tanabata kyou". His pendant, showing 7 points (similar points like a hanko art), is shown missing.

Kogoro Mouri is invited to a big conference about a large murder case. Conan tags along and eavesdrops. Almost every policeman is invited to this case. Yamamura-keiji is promoted to Inspector. The police explain that 6 people have died in what seems to be a serial murder case. So far, however, the only known link is that the six have all lost a pendant. After the conference, Yamamura comes back from toilet humming a melody. Conan realizes that the song is "Nanatsy no ko" and asks why Yamamura is humming it. Yamamura replies that he had just heard it from some beeps from a cell phone. Conan tries to find the owner of the cell phone, but all he sees is someone boarding Gin's car just in front of the police department. After his return, he tells the Agasa and Haibara. All three agree that the mystery passenger was most likely Vermouth as she can perfectly disguise herself and is the right height. As Conan is left wondering what interest the Black Organization has in that case, Haibara warns him not to go too far.

In a shopping mall, the police are trying to catch 2 suspects, a man and a woman, of the serial murder case. They managed to surround the pair, but Yamamura tumbles and loses his police badge. The man uses a knife holds a nearby woman hostage. Conan manages to shoot the knife with his ball out of the man's hand. His accomplice manages to retrieve the knife and aims at Kiyonaga Matsumoto but the attack is intercepted by Megure. The knife hits his stomach, and he says, "It's alright; I'm 'fat' enough."

The woman who was used to threaten the police has vanished. Conan follows her to her car and finds a disguised Vermouth. She says that the Black Organization needs a memory card and a new member, "Irish". The suspects gain an alibi because another person was killed during the time of the chase. Satou starts to suspect that a police officer is involved in the case.

Later, the children find another taped beetle in the park. Meanwhile, Conan tries to find the solution to this case. He is curious about the dying message. He and Heiji find out that there was a fire accident in a hotel in Kyoto and a young woman (Nana) died. Conan tracks the family and the neighbor and asks some questions. Soon also the police find this track. In the end the lover of the dead woman lurks around and might be the culprit. Soon Conan realizes that the two might have done star gazing and realizes the crime scenes are ordered like the star constellation Ursa Major. So he knows where the last crime takes place: Toho Tower.

The Shounen Tantei wanting to find out the secret of the taped beetle goes to the park. Also some art of Conan at school has been damaged and the helmet of the black knight (Shinichi) has vanished. A person then found out that Conan is Shinichi. This person asks Gin if he could remember Kudo Shinichi. Conan goes to Toho Tower where many people dressed in Kimonos are there for a visit. It is also shown on TV where Sonoko notices him. Soon Ran calls Sonoko as she is worried as it is so late and Conan still has not at home. Sonoko tells her that Conan went alone to Toho Tower.

It is also soon that the police get the hint of the star constellation (by Yamamura and Kogoro) and leaves for Toho Tower.

The children find a small house where someone seems to be kept. They are afraid as soon someone steps behind them. It's Agasa and Haibara. Agasa calls Satou and she says to Takagi that they changed the destination and that it is important.

Soon the police arrive and nobody else seems to be at Toho Tower anymore. Of course Conan and the lover of Nana are there. They are talking until one of the family members of Nana appears. The connection is a hotel in Kyoto where Nana and her boyfriend stayed. A fire kind of broke out and Nana died because she wasn't in the last elevator. That elevator only holds 7 people and with her there were 8 people. The lover thought one of the 7 must have pushed her out but the other family member says that she herself stepped out. He was the last of the 7 in the elevator. He is strong and has a knife with him. He is threatening Conan and the lover. Soon someone shoots the knife out of his hands - Matsumoto.

Conan realizes that Matsumoto is not the real one but Irish in perfect disguise. Irish then says he doesn't want to kill Conan and he's the one who found out his identity but didn't tell anyone yet. Conan wants to have the memory card but Irish refuses to hand it over. It is also said that Irish is a very good friend of Pisco who was killed by Gin.

A fight start between those two and as Irish is strong and clever and has a gun all of Conan’s gears are knocked out. Soon Ran arrives at Toho Tower and wants to find Conan. She finds him but has to encounter Irish (still as Matsumoto). She makes some good Karate hits but he is too strong for her. Then Irish and Conan fight outside near the top as soon a helicopter with Gin, Vodka, Korn and Chianti arrives. Irish shows them the card and Gin orders Chianti to shoot him and the card. Irish is barely alive. Then Gin notices Conan and tries to shoot him. Irish protects Conan and dies. He also said that Vermouth told him that he can trust Kudo Shinichi.

The BO tries to shoot Conan and slightly destroyed the upper levels of the Toho Tower. In a pinch close to death, Conan doesn't know what to do until he finds a heavy lamp and his lifting gear. He throws the lamp with the lifting gear against the helicopter as it starts to explode. The BO flies away (near Roppongi Hills Mori Tower) and the helicopter crashes into a park with the fate of the 4 BO members unknown. Vermouth drives away and says: That was to be expected from her silver bullet.

The final scene of the movie shows the real Matsumoto inside the small house found by the Detective Boys.