Mission of the Galactic Salesman

This is a science fiction adventure novel about a galactic salesman and his mission to link Earth's telephone network with his home star system of Sirius B. He makes a deal with 8 teenagers, and they help him build a galactic communications device. In exchange for the favor, the galactic salesman gives the teenagers the gift of teleportation by thought, and they take off and have adventures to different places of Earth and also to other star systems like Sirius B, Vega, and the Pleiades. One of their adventures involves searching for the lost ancient crystal stolen from Atlantis over 15,000 years ago.