Secret Files 3 (German: Geheimakte 3) is a graphic adventure video game developed by Animation Arts and published by Deep Silver for Windows iOS, Android and Nintendo Switch.

The mystery of Tunguska comes full circle as Nina embarks on one final continent-spanning journey to save Max and the world.

In Alexandria of Egypt in 48 BC two people in black robes pay the thief Menis-Ra to destroy some papyrus scrolls kept in the city's library.

She finds that in the last months Max was interested in an excavation site in Potbelly Hill in southeastern Turkey, where he was called by Emre Dardogan.

Apparently in the site they discovered a gigantic temple complex built over 11.000 ago (way before the Egyptian pyramids or Stonehenge) by people who vanished 2000 years later as if never existed.

While on the plane, she searches the laptop further and discovers that the amphora from Alexandria was found in a river in 1477 AD and that it was going to be sold by an Arab to a merchant in Florence.

Da Vinci hides the scroll because it contains a solution to a mathematical problem by Archimedes and he doesn't want it to fall into the wrong hands.

She finds the painting and has another flashback, this time with Archimedes explaining to the king of his country that he discovered that the mathematical constant of pi contains a secret: the key to the knowledge of the world and eternity.

Nina is put to an induced coma, similar to a technical death, to see the end of the world which will come by the Guardians.

In her state of near death, she's got 3 minutes available to find the Guardians, before Jane and Max have to wake her up to prevent permanent brain damage.

He mentions the Fermi paradox (the notion that, with the numerous galaxies in the universe, there has to be extraterrestrial life somewhere, but, for some reason, they haven't contacted Earth yet) and the constant of pi (greek «π»).

Before he tells Nina where she can find him in real life, or what the machine (if created) is meant to be used for, the 3 minutes pass, so Jane and Max awaken her.

He says that the reason why extraterrestrial life forms haven't contacted Earth is because each one of them, at different ages, have become technologically advanced to the point they invented computers, solved the secret of the universal constant of pi and constructed the machine.

Regardless of the player's choice, Jane Cunningham gets the deterrium and escapes with the submarine, but she leaves her bag behind, containing the antidote, so Max is saved.