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Never fear I can in fact remember more about it than that! The cover was black and it had a silver snake eating its own tail on the cover. The book was about a boy who is hired by a company to travel (with a girl and another boy (the drummer)) to another world/alternative reality and there they discovered another girl who turned out to be his dead twin sister.
He was some hero or something and they found something out about the company they were hired by and at one point he was almost killed but got a scar next to his right (or maybe left) eye that made him or marked him as the seer? His twin gave him a bracelet shaped like a snake biting its own tail and that meant something important... The Snake was also the symbol/logo of the company.
In the end he went home and spoke to him mom about his twin and I remember it being the first book in a series.