This idea arose after the birth of Mary's first son, William, born
January 24, 1816, who was destined to be only for a few short years
the joy of his parents, and then to rest in Rome, where Shelley was
not long in following him.

It is evident from Godwin's diary that Claire must have been on a
visit or in direct communication with Mary at the beginning of
January, as Godwin notes "Write to P.B.S. inviting Jane"; and it does
not seem to have been possible for Shelley and Mary to have borne
resentment. The facts of this meeting early in the year, and that Mary
and Shelley contemplated another of their restless journeys abroad,
certainly take off from the abruptness of their departure for Geneva
in May with Claire Claremout. Undoubtedly Shelley was in a worried and
excited state at this period, and he acted so as to rouse the doubts
of Peacock as to the reason of the hurried journey. The story of
Williams of Tremadock suddenly appearing at Bishopsgate, to warn
Shelley that his father and uncle were engaged in a plot to lock him
up, seems without foundation. But when, in addition to this story, we
consider Claire's history, we can well understand that, in spite of
Shelley's love of sincerity and truth, circumstances were too strong
for him. At a time when he and Mary were being avoided by society for
openly defying its laws, they might well reflect whether they could
afford to avow the new complication which had sprung up in their small
circle. Claire, in hopes of finding some theatrical engagement, had
called upon Lord Byron at Drury Lane Theatre, apparently about March
1816, during the distressing period of his rupture with his wife. The
result of this acquaintance is too well known, and has been too much a
source of obloquy to all concerned in it, to need much comment here,
and it is only as the facts affect Mary that we need refer to them at
all.