Blood trail

A blood trail was a technique developed by the Nightsisters of Dathomir. They believed it was the domain of their Fanged God, who governed hunting and was an embodiment of darkness, and with this technique, the Nightsister would use her own blood to mark her target (often a slave) and track them through the blood mark using the Force in case they escaped. The shed blood used for a blood trail could not be removed once the trail was set.

Mother Talzin claimed in her Wild Power writings that the technique was known only to the Nightsisters. Prior to the Clone Wars, Asajj Ventress used this technique to hunt down the defeated warlords of Rattatak even after they had surrendered their thrones to her. Ventress later wrote of her use of the blood trail in Wild Power, and the writings came into the possession of of the Sith Lord Darth Sidious, who compiled it into the Book of Sith.

Darth Caedus used this Force technique on his sister, Jaina Solo during the Second Battle of Roche in 41 ABY, with the intent that it would lead him to the hidden Jedi base. It was noted by Jaina as feeling acidic. Later, by 43.5 ABY, Luke Skywalker had also learned this technique; he used it to track the Sith apprentice Vestara Khai after their duel on Sinkhole Station. Skywalker eventually tracked Khai to Dathomir.