Here I attempted to combine an origin story for the Master's ability to shapeshift into an indestructible plasmalike snake in order to move between stolen bodies, as seen in the Doctor Who tv movie (1996), with the offscreen death of Indiana Jones' mother (The Young Indiana Jones Chronicles). While Anna Jones' body is shown here to begin seriously deteriorating almost instantly, the body which the Master assumed in the tv movie lasted him a couple of days, which correlation of facts I intended to imply that each body he stole while making use of the plasma snake form varied widely in its longevity for him. If Anna was genuinely sick with whatever it was that screen continuity attributed her death to (at this writing I don't remember what that was) then that'll be why her body didn't last the Master as long as did the body of Bruce the ambulance driver.