Silt is first seen when Needlepaw takes Sleekpaw and Violetkit to where Darktail's rogues are. The she-cat is seen sliding from a clump of bracken, her dirty white pelt glowing dim in the moonlight, with a black she-cat walking beside her. After a short conversation about the Clans, Needlepaw introduces her Clanmates to the rogues, including Silt. The silver she-cat acquaints Violetkit and Sleekpaw with Darktail's group, but Silt leans forward and demands why ShadowClan lets Violetkit live with them, despite her not being born in the Clan. The kit answers that she doesn't know.
Later, when Violetkit has tell Darktail's rogues that Needlepaw couldn't meet them, she finds the group, and the rogue leader notes that she must be hungry. He calls to Nettle, and the brown tabby pads out of the shadows with a rabbit, followed by Silt who carries a squirrel. The cats eat the food but end up falling asleep, and when Violetkit wakes at dawn and alerts Darktail about her need to get back to her camp, he notes that it must be that the fine prey that Nettle and Silt caught for them made them sleepier than expected.
Moons after, when several young ShadowClan cats have joined Darktail's group, Violetpaw and Needletail return to camp with Rain and Sleekwhisker, who have caught little prey, and she notes that Darktail had began to notice the smaller amounts of prey that the two had been bringing back. She thinks that at least with Silt and Beenose sick, they wouldn't want to eat. Once the four cats have come back to the camp, Rain asks Roach how Silt and Beenose are, while glancing toward the bush where the sick cats were sheltered. Nettle noses his way out of the bush out and answers that they are worse, as Beenose keeps coughing and Silt's fever is rising.
When Darktail and his cats take over ShadowClan, it is said every rogue cat is there except Beenose. However, Silt was confirmed by Kate to have died of yellowcough before Darktail took over.
Rain: "How are Silt and Beenose?"
Nettle: "They're worse. Beenose keeps coughing, and Silt's fever is rising."