Remember Treasure Travail? This time the magical demon has captured an eminent archeologist, who is in search of an invaluable, long lost scroll. As before, the demon secretly summons the scroll using his magical powers. Next day, the demon brings the archeologist in front of 3 doors.
The demon explains that:

1. Precisely one of the rooms contains the scroll, one room is empty and the remaining room contains the lion.
2. The sign on the room containing the scroll was true, the other sign on the room with the lion was false and the sign on the door of the empty room could be either true or false.

Here are the three signs:

+-----------+   +--------------+   +-----------+ 
|    I      |   |    II        |   |   III     |
| ROOM III  |   | THE LION IS  |   | THIS ROOM |
| IS EMPTY  |   |  IN ROOM I   |   | IS EMPTY  |
+-----------+   +--------------+   +-----------+

If the archeologist chooses the room with the scroll or the empty room, he is to be set free. If he chooses the room with the lion, the demon will lock the door as soon as he enters it, and the lion will kill him.
The writings on the scroll contained invaluable information about history of the humankind. Therefore, although the empty room was preferable to the one with the lion, naturally his first choice lay with the room having the scroll.
Which room contains the scroll, which one contains the lion and which is the empty room? Provide adequate reasoning for your answer.