Книга A Leap Across the Abyss

The Earth Federation prepares to repel an attack of the new enemy.
Fleet Admiral Igor Lavroff feels confident of victory, knowing that Imperial warships will take part in the upcoming battle along with his fleet.
But strange things begin to happen in the Empire, and it suddenly turns into a highly unreliable ally, leaving humans and the lizards alone with the enemy they are unable to fight on equal terms.