main and builds the Chateau de
l'Aiguille. Where does he select his site? In the Midlands of France,
with the result that the curious are thrown off the scent and do not
hunt about in Normandy.

Rouen, Dieppe, the Havre--the Cauchois triangle--everything lies there.
On one side, the sea; on another, the Seine: on the third, the two
valleys that lead from Rouen to Dieppe.

A light flashed across Beautrelet's mind. That extent of ground, that
country of the high tablelands which run from the cliffs of the Seine
to the cliffs of the Channel almost invariably constituted the field of
operations of Arsene Lupin. For ten years, it was just this district
which he parcelled out for his purposes, as though he had his haunt in
the very centre of the region with which, the legend of the Hollow
Needle was most closely connected.

The affair of Baron Cahorn?[3] Or the banks of the Seine, between Rouen
and the Havre.

[3] The Seven of Hearts, by Maurice Leblanc. II; Arsene Lupin in Prison

The Thibermenil case?[4] At the other end of the tableland, between
Rouen and Dieppe.

[4] The Seven of Hearts. IX: Holmlock Shears Arrives Too Late.

The Gruchet, Montigny, Crasville burglaries? In the midst of the Caux
country.

Where was Lupin going when he was attacked and bound hand and foot, in
his compartment by Pierre Onfrey, the Auteuil murderer?[5] To Rouen.

[5] The Seven of Hearts. IV: The Mysterious Railway-passenger.

Where was Holmlock Shears, Lupin's prisoner, put on board ship?[6] Near
the Havre.

[6] Arsene Lupin versus Holmlock Shears, by Maurice Leblanc,
Chapter V: Kidnapped.

And what was the scene of the whole of the present tragedy? Ambrumesy,
on the road between the Havre and Dieppe.

Rouen, Dieppe, the Havre: always the Cauchois triangle.

And so, a few years earlier, possessing the pamphlet and knowing the
hiding-place in which Marie Antoinette had concealed the document,
Arsene Lupin had ended by laying his hand on the famous book of hours.
Once in possession of the document, he took the field, "found" and
settled down as in a conquered country.

Beautrelet took the field.

He set out in genuine excitement, thinking of the same journey which
Lupin had taken, of the same hopes with which he must have throbbed
when he thus went in search of the tremendous secret which was to arm
him with so great a power. Would his, Beautrelet's efforts have the
same victorious results?

He left Rouen