A cartridge assembly for use in an aerosol-generating system, the cartridge assembly comprising: a cartridge comprising: at least one compartment having an air inlet (16, 18) and an air outlet; and at least one cartridge actuation portion on an outer surface of the cartridge; a mouthpiece comprising: a mouthpiece cavity, wherein a downstream end of the cartridge is received within the mouthpiece cavity; a mouthpiece wall portion extending across a downstream end of the mouthpiece cavity, the mouthpiece wall portion comprising a mouthpiece air inlet; and a mouthpiece actuation portion on an inner surface of the mouthpiece cavity and engaged with the at least one cartridge actuation portion; and a cartridge cover comprising: a cartridge cover cavity, wherein an upstream end of the cartridge is received within the cartridge cover cavity; a cartridge cover wall portion extending across an upstream end of the cartridge cover cavity, the cartridge cover wall portion comprising a cartridge cover air inlet; and a cartridge cover actuation portion on an inner surface of the cartridge cover cavity and engaged with the at least one cartridge actuation portion; wherein the at least one cartridge actuation portion and the cartridge cover actuation portion are configured so that the cartridge cover is helicoidally moveable with respect to the cartridge from a first position in which the cartridge cover wall portion abuts an upstream end of the cartridge and obstructs the air inlet (16, 18) of the at least one compartment, to a second position in which the cartridge cover wall portion is spaced apart from the upstream end of the cartridge and the cartridge cover air inlet is in fluid communication with the air inlet (16, 18) of the at least one compartment; and wherein the at least one cartridge actuation portion and the mouthpiece actuation portion are configured so that the mouthpiece is helicoidally moveable with respect to the cartridge from a third position in which the mouthpiece wall portion abuts a downstream end of the cartridge and obstructs the air outlet of the at least one compartment, to a fourth position in which the mouthpiece wall portion is spaced apart from the downstream end of the cartridge and the mouthpiece air inlet is in fluid communication with the air outlet of the at least one compartment. a cartridge comprising: at least one compartment having an air inlet (16, 18) and an air outlet; and at least one cartridge actuation portion on an outer surface of the cartridge; at least one compartment having an air inlet (16, 18) and an air outlet; and at least one cartridge actuation portion on an outer surface of the cartridge; a mouthpiece comprising: a mouthpiece cavity, wherein a downstream end of the cartridge is received within the mouthpiece cavity; a mouthpiece wall portion extending across a downstream end of the mouthpiece cavity, the mouthpiece wall portion comprising a mouthpiece air inlet; and a mouthpiece actuation portion on an inner surface of the mouthpiece cavity and engaged with the at least one cartridge actuation portion; and a mouthpiece cavity, wherein a downstream end of the cartridge is received within the mouthpiece cavity; a mouthpiece wall portion extending across a downstream end of the mouthpiece cavity, the mouthpiece wall portion comprising a mouthpiece air inlet; and a mouthpiece actuation portion on an inner surface of the mouthpiece cavity and engaged with the at least one cartridge actuation portion; and a cartridge cover comprising: a cartridge cover cavity, wherein an upstream end of the cartridge is received within the cartridge cover cavity; a cartridge cover wall portion extending across an upstream end of the cartridge cover cavity, the cartridge cover wall portion comprising a cartridge cover air inlet; and a cartridge cover actuation portion on an inner surface of the cartridge cover cavity and engaged with the at least one cartridge actuation portion; a cartridge cover cavity, wherein an upstream end of the cartridge is received within the cartridge cover cavity; a cartridge cover wall portion extending across an upstream end of the cartridge cover cavity, the cartridge cover wall portion comprising a cartridge cover air inlet; and a cartridge cover actuation portion on an inner surface of the cartridge cover cavity and engaged with the at least one cartridge actuation portion; wherein the at least one cartridge actuation portion and the cartridge cover actuation portion are configured so that the cartridge cover is helicoidally moveable with respect to the cartridge from a first position in which the cartridge cover wall portion abuts an upstream end of the cartridge and obstructs the air inlet (16, 18) of the at least one compartment, to a second position in which the cartridge cover wall portion is spaced apart from the upstream end of the cartridge and the cartridge cover air inlet is in fluid communication with the air inlet (16, 18) of the at least one compartment; and wherein the at least one cartridge actuation portion and the mouthpiece actuation portion are configured so that the mouthpiece is helicoidally moveable with respect to the cartridge from a third position in which the mouthpiece wall portion abuts a downstream end of the cartridge and obstructs the air outlet of the at least one compartment, to a fourth position in which the mouthpiece wall portion is spaced apart from the downstream end of the cartridge and the mouthpiece air inlet is in fluid communication with the air outlet of the at least one compartment.