Under the battlemented cornice of the curtain-wall to the west a row of heads is painted in fresco on a red ground, which seems to be part of the same scheme with the curious heads on the plinth of de Marchia's tomb: one of these, a woman in a dark-coloured hood, is especially distinct. No doubt, the whole wall was originally painted. The sill of the window over the tomb seems to have been used for some special purpose: there is a passage cut through the splay of the window, through which the sill may be reached, which is not the case with the corresponding window of the north transept. The passage is reached from a staircase concealed behind the curtain-wall, which is reached by an ogee-headed doorway (with cusps in the head, finial, and two small heads to its very beautiful mouldings). This staircase also leads to a chamber on the level of the passage, but on the west side: the interior of the chamber can be seen from the ground, as its old wooden door is kept open. It is supposed by some to have been a watching chamber in connection with the tomb. There can, indeed, be little doubt that these arrangements had something to do with de Marchia's tomb, or that the ornamented doorway in the curtain wall of the same date as the tomb, together with the frescoes on the wall, were connected with the strong efforts that were made at this time for his canonisation. Perhaps the sill was used for the display of his relics, and the chamber was the ordinary resting-place of the reliquary, for which purpose the door and the absence of windows would have fitted it.