Theseis

Theseis was a third-person adventure game, created by the Greek development group Track7 Games. The game was set in modern day Greece, and followed the story of Andronicus Kalogirou and his stepsister Pheve Kalogirou, as they search for their missing, and presumed dead, stepfather.

Story
Andonicos Kalogirou is a man devoted to science and the war against superstition. From his office in the historic centre of Athens, he has worked diligently for more than 5 years, traveling all over Greece and revealing the paranormal for what it truly is: drunken fantasies and uneducated hysteria. But his intelligible, safe little world is going to come crushing down when a call from Pheve, his adopted sister and fervent advocate of the mythic, informs him that his stepfather is not only missing, but presumed dead as well. With a heavy heart, Andronicos travels to the place of his childhood, high atop the Greek mountains, to bury an empty coffin and reunite with his quarrelsome stepsister. Little does he know that each step irrevocably brings him and Pheve closer to what Destiny has in store for them. For the death of their stepfather heralds the beginning of the greatest struggle between good and evil with the prize being nothing less than the very future of this world.

From the hidden network of caves beneath the Greek metropolis, crawling with the remnants of a bygone age and the treasures of the past, to long lost places of legend all over Greece, Andronicos and Pheve struggle to uncover the pieces of an ancient conspiracy, kept secret through stealth and murder. But what they find could well be just the tip of the iceberg. For beneath the cover of shadows and time, a great power lay dormant, waiting for the time when it will once again come forth to the light of day, back amongst the people where it belongs.

Cancellation
One of the game's developers and the community manager have confirmed that the game is no longer in development and the company has shut down since 2009.