The present invention relates to a cartridge (10), comprising: An outer shell (20) defining an inner volume containing: A first reservoir (30) containing a first component and having a first aperture (32) for discharge of the first component； a second reservoir (40) containing a second component and having a second aperture (42) for discharge of the second component； A first removable film (34) impermeable to the first component sealing the first aperture； A second removable film (44) impermeable to the second component sealing the second aperture； A seat (12) having an opening (14) in said outer shell and delimiting walls within said inner volume, said first and second apertures being formed in said delimiting walls, the seat being configured to house a piercer (50) of an external component； and Wherein a portion of the first film or a portion of the second film is protruding from said opening or it faces said opening. The present invention also relates to a system for an aerosol-forming article (1000) and to a method for opening a cartridge in an aerosol-forming article.
