A drive mechanism for a medicament delivery device , comprising: a base member having a guide track structure , the guide track structure including a first track and a second track , a rotator base member having a first guide structure configured to run in the first track , a rotator housing coaxially arranged with and configured to engage with the rotator base member , the rotator housing having a second guide structure arranged at a fixed distance from the first guide structure and configured to run in the second track , a rotation device configured to actuate the rotator housing , and a medicament container carrier configured to receive a medicament container , wherein the medicament container carrier is coaxially arranged relative to the rotator base member and the rotator housing , the rotator housing being configured to rotate relative to the medicament container carrier , characterised in that the first track and the second track are arranged relative to each other such that actuation of the rotator housing causes the second guide structure to move along the second track and the first guide structure to initially move in a first direction along the first track and subsequently to move in a second direction opposite to the first direction, the movement in the first direction causing initial linear movement of the medicament container carrier in the first direction, the movement in the second direction causing subsequent movement of the medicament container carrier in the second direction, and movement of the second guide structure along the second track causing rotation of the rotator housing relative to the base member and the medicament container carrier , thereby enabling a medicament delivery. a base member having a guide track structure , the guide track structure including a first track and a second track , a rotator base member having a first guide structure configured to run in the first track , a rotator housing coaxially arranged with and configured to engage with the rotator base member , the rotator housing having a second guide structure arranged at a fixed distance from the first guide structure and configured to run in the second track , a rotation device configured to actuate the rotator housing , and a medicament container carrier configured to receive a medicament container , wherein the medicament container carrier is coaxially arranged relative to the rotator base member and the rotator housing , the rotator housing being configured to rotate relative to the medicament container carrier , characterised in that the first track and the second track are arranged relative to each other such that actuation of the rotator housing causes the second guide structure to move along the second track and the first guide structure to initially move in a first direction along the first track and subsequently to move in a second direction opposite to the first direction, the movement in the first direction causing initial linear movement of the medicament container carrier in the first direction, the movement in the second direction causing subsequent movement of the medicament container carrier in the second direction, and movement of the second guide structure along the second track causing rotation of the rotator housing relative to the base member and the medicament container carrier , thereby enabling a medicament delivery. <EOS>