Warhammer 40k - Space Marine Battles Novella - Shadow Captain by David Annandale

On Lepidus Prime, the beleaguered Space Marines have an unlikely ally – the eldar of Craftworld Saim-Hann. With these ancient enemies of mankind engaging the ork invaders, Shadow Captain Krevaan of the Raven Guard sees a chance to strike back against the greenskins. Forging a fragile alliance with the eldar, Krevaan prepares to stop the orks before they can despoil the vital city of Reclamation. But the Raven Guard, no strangers to hidden agendas, suspect a sinister motive to the eldar actions…