Letter card from Walter Lynn to his Mother

Walter wrote
"My Dear Mother
We have only got so far yet have been here 2 days. I saw Sarah on Wed afternoon, left Spalding about 8 got in London about midnight and stayed at the YMCA. I couldn't say when we are going over. Will write you again when I land. We got a raid warning last night. Haven't much news. hope John is better by now. my cold is still bad.
Love to all
Your affectionate Son
Wal"

Walter had obviously been home on leave and had gone back by train. Sarah was his sister, who lived in Spalding. John was his brother, who died in 1918. I think he died at home, and I was told he died in the flu epdemic, but I'm not sure if that is correct.