An entry with a bang

October, 1957. The dawn of the Space Race. And, for Earth, the start of a race of another kind, although they don't know it yet. A bubble centered on the Earth of Tom Clancy's Jack Ryan series, 100 light years in diameter, is deposited on the outer edges of the Inner Sphere, in the BattleTech universe. Almost five decades after the event, Earth is visited by strangers from the Inner Sphere of 3020, and they're not visiting peacefully.