|This article is about a/an episode in Kamen Rider Drive.|
What Is in the Belt's Past? (ベルトの過去になにがあったのか Beruto no Kako ni Nani ga Atta no ka) is the tenth episode of Kamen Rider Drive.
Special Investigation Unit discovered that Shinnosuke's birthday is around the Christmas Eve, December 24 but he didn't excited about it due to receiving only one gift that represent both birthday and Christmas gift each year. While debating for Shinnosuke's gift, suddenly a strange blackout occur within the city which even affected several cars and even backup electricity supplies. Mr. Belt and Tridoron seemed unaffected due to their Core Driviars.
Somewhere in the location of Volt Roidmude's demise, Volt was revived again when several lightning bolts struck his device. Back at the Unit's base, they realised that Volt was seen again by several citizens in his human form, Goro Minami. According to Genpachiro, the real Goro Minami died three months earlier and Volt also supposedly met his demise after Drive killed him. Searching for clues regarding the late author in a library, they found his final works, The Dark Eve which was about a mad revolutionist creating a city-wide blackout, hinting Volt's plan but the story remained unfinished since he had died sometime later. Chase appeared in the library and challenged Shinnosuke to a fight. When Heart tried to join the fray, Mr. Belt orders them to retreat.
At the Drive Pit, he revealed to Shinnosuke that Heart was his murderer during his final days as a human named Krim Steinbelt. Bringing Shinnosuke to his mansion's ruin, he revealed his history: Fifteen years ago, his friend Dr. Banno made three advanced androids called Roidmudes. However, when his development had hit the dead end, he pleaded Krim's help as he gave the prototype of Core Driviars but soon it made the first three Roidmudes rebel and kill Dr. Banno as well as Krim Steinbelt. Fortunately, he uploaded consciousness into the Drive Driver. Before the Global Freeze, he managed to call forth Protodrive and beginning the operation to destroy all Roidmudes.
Revisiting Volt Ridmude's hideout, Kiriko stumbled upon Goro Minami's magazine when suddenly a Heavy Acceleration wave released. Volt communicated with Kiriko via a phone, telling her that he "no longer existed" in this world but his creation would exist to relaunch the Dark Eve and cancelled the Heavy Acceleration wave. She passed the information to Shinnosuke but as he went out, Heart stopped him and revealed that he was the first Roidmude to evolve and "killed" Protodrive. Refusing Mr. Belt's orders, Shinnosuke as Drive fights Heart even with the help of Shift Cars and Tridoron but he resisted and became stronger compared to his earlier days when killing Protodrive. Heart lifts Drive and prepared to initiate Dead Zone but Drive as Type Technic pumped electricity to accelerate the process, willing to sacrifice his own life in order to kill Heart as he ordered Belt to leave.
- Shinnosuke Tomari (泊 進ノ介 Tomari Shinnosuke): Ryoma Takeuchi (竹内 涼真 Takeuchi Ryōma)
- Kiriko Shijima (詩島 霧子 Shijima Kiriko): Rio Uchida (内田 理央 Uchida Rio)
- Jun Honganji (本願寺 純 Honganji Jun): Tsurutaro Kataoka (片岡 鶴太郎 Kataoka Tsurutarō)
- Rinna Sawagami (沢神 りんな Sawagami Rinna): Rei Yoshii (吉井 怜 Yoshii Rei)
- Kyu Saijo (西城 究 Saijō Kyū): Kenta Hamano (浜野 謙太 Hamano Kenta)
- Genpachiro Otta (追田 現八郎 Otta Genpachirō): Taira Imata (井俣 太良 Imata Taira)
- Narration (ナレーション Narēshon), Drive Driver's voice (ドライブドライバーの声 Doraibu Doraibā no koe): Chris Peppler (クリス・ペプラー Kurisu Pepurā)
- Chase (チェイス Cheisu): Taiko Katono (上遠野 太洸 Katōno Taikō)
- Heart (ハート Hāto): Tomoya Warabino (蕨野 友也 Warabino Tomoya)
- Kamen Rider Drive: Seiji Takaiwa (高岩 成二 Takaiwa Seiji)
- Mashin Chaser: Yasuhiko Imai (今井 靖彦 Imai Yasuhiko)
- Heart Roidmude: Yohei Fujita (藤田 洋平 Fujita Yohei)
- Car Used:
- Type Change: Shift Speed, Shift Technic, Shift Wild
- Tire Exchange: Midnight Shadow, Spin Mixer
- Type Used:
- As part of Super Hero Time, this episode aired alongside Ressha Sentai ToQger episode 40, Station 40: Who Is He? He Is Whom?.
- Viewership: 5.5%
- Closing Screen Shift Car
- Roidmude Count
- Answer to the episode's question: The Belt was Krim, his friend invented the Roidmudes, the first three Roidmudes attacked Krim's mansion, and Heart defeated Protodrive.
- This is the first episode Brain doesn't appear in since his debut. However in episode 26, Roidmude 003 in Mr. Belt's flashback would revealed as Brain's Low-Class form.
- This is the first episode where Drive does not assume a Tire Exchange mode in Type Wild and Type Technic.
- Final appearance of Drive's Type Speed Mixer.
Kamen Rider Drive Volume 3 features episode 9-12: How Can I Get Used to the Cool Body?, What is in the Belt's Past?, Who Can Prevent the Dark Christmas Eve? and Where Did That White Kamen Rider Come From? 
Collection 1 comes with 12 episodes.
- TV Asahi's official summary for 「ベルトの過去になにがあったのか」
- Toei TV's official episode guide for 「ベルトの過去になにがあったのか」