The man might have died in a fit; but then the jewels are...

The man might have died in a fit; but then the jewels are missing," mused the Inspector, "Ha! I have a theory. These flashes come upon me at times... What do you think of this, Holmes? Sholto was, on his own confession, with his brother last night. The brother died in a fit, on which Sholto walked off the treasure! How's that?" "On which the dead man very considerately got up and locked the door on the inside," said Holmes.