Rem's Death Note

“''This is the notebook that was left behind when Rem died. Light then picked it up and gained ownership. During the battle with Mello, this notebook was given to the task force in order to attack the mafia members.''” —Death Note: How to Read 13

Rem's Death Note is the third notebook used in the series, and is owned by Rem until her eventual  death.

Appearance
Rem's Death Note is plain, with no writing on it. The color of it is black like most other Death Notes.

Manga and Anime
Rem's Death Note remains in her possession until her death. She uses it to protect Misa by killing Watari and then L. This act causes her to die and turn to dust, then her notebook is left behind, making it property of the Human World. Light retrieves the notebook from Rem's ashes and then ownership of the notebook is taken by Light.

Years later, Light gives it to Ryuk in order to make him the Shinigami attached to it. Light then keeps it until he gives it to the Task Force to use against the Mafia. Soichiro becomes the holder of the notebook, and makes the trade with Ryuk for the Shinigami Eyes. Aizawa brings the notebook to the Yellowbox Warehouse, and the notebook is later burned by Near, causing it to disappear from the Human World.

Live Action Films
In the live action films, Light and the task force never gain this notebook. Rem destroys it in order to prevent Light from ever being able to use it, then she dies saving Misa.