Defending the Vanguard — John Thornton

In book 7 of the Colony Ship Vanguard series there are many exciting adventures. Paul, Gretchen, Brinley, and Larissa are seeking to find ways to counter the threats to the ship, its biological habitats, the flora and fauna, and especially the humans. The alien forces are brutally seeking to take over. What will happen as the humans work at defending the Vanguard?