Merlin: The complete fourth season

disc 1. The darkest hour. pt. 1

The darkest hour. pt. 2

The wicked day

Althusa

disc 2. His father's son

A servant of two masters

The secret sharer

Lamia

disc 3. Lancelot du Lac

A herald of the new age

The hunter's heart

The sword in the stone, pt. 1

disc 4. The sword in the stone, pt. 2

Bonus features.