Abstract: In some embodiments, a reconstitution or medicinal fluid delivery device includes a transfer engine including two fluidly connected spikes, each configured to pierce a container. A check valve may be disposed between the two spikes to allow unidirectional flow from one container to the other. Physical access to a fluid outlet may be obstructed by a housing until the reconstitution or medicinal fluid delivery device is actuated, whereupon physical access to the fluid outlet is permitted. The reconstitution or medicinal fluid delivery device may be placed on a flat surface and actuated with force applied in a single direction toward the flat surface.