L's successor

L's heir or L's successor is the person to succeed L if anything should happen to him.

Overview
L is known to all as the worlds greatest detective, and his opinion is highly valued by world government officials. His status allows him to mobilize law enforcement whenever he needs them.

L remains hidden and communicates with the outside world via computer. He uses an electronic voice synthesizer to cover his voice, and his real name and appearance are unknown by the public.

Due to the dangers that come with being a world renowned detective, L's life is assumed to be at risk. If anything should happen to L, L's successor will assume the position as the greatest detective in the world.

Main Article: Wammy's House
Little is known about how one is chosen to be a successor, though it seems that L himself chooses. The child is assumed to be a resident at Wammy's House, an orphanage created by L's mentor, Quillish Wammy (aka Watari).

Near and Mello
L has two successors, Near and Mello. It appears that they were chosen at a young age, with Near being thirteen and Mello close to fifteen when they were introduced in the story. Of the two children, only one was intended to gain the title of L, but because of L's death neither child was officially picked. After learning of L's death, Roger proposed to the two that they work together. Near agreed, but Mello found it impossible to work with Near and gave Near the position as L.

Main Article: Death Note One-Shot Special
As shown in the manga one-shot taking place three years after the main storyline, Near remains the current L and solves cases under the L name.

Main Article: Death Note: Another Note
The Novel, Death Note: Another Note greatly expands on information regarding L's successors. Within the novel, two other successors are introduced: B and A. These two are reffered to as the "first generation" of successors, having been chosen before Near and Mello. The first successor, A was unable to cope with the pressure of having to succeed L, and committed suicide. The second, B became a serial killer and was later killed by Kira while in prison.