Possible Clues:

• Gain lost ground — start to abridge "Remembrance of Things Past"
• Cast gains a lot from dreams of home
• Feeling of longing for the Before Times
• Homesickness caused by reacting to a signal
• Lots again unhappy, longing for the past
• Giant also represented in a longing for things past
• Longing, looking back again, lots fancy
• Longing for battle, lost again
• Lost again (anag) — hankering for the past
• Lost again in reverie about the past ...