The Concubine's Fourth Child and Rise to Empress

In the imperial harem, concubines fight for the emperor's favor. The imperial noble consort is pregnant with her fourth child, due soon, while the empress position is vacant. Factions watch the birth outcome. Some plot to sabotage the noble consort, while others aid her. In the end, the noble consort safely gives birth and is promoted to empress relying on the emperor's favor.