Written to Mr. Kirkby, Lewis explains that his R. A. F. commitments cause him to decline future invitations."...I shall then be in the last (and most hectic) week of term... and even in the vacation, I am so heavily committed to the R. A. F. that I can do little else. With much regret...." He signs, "C. S. Lewis."
Lewis' brief letter alludes to his tour of R.A.F. bases to give talks on Christianity, an outgrowth of his popular BBC broadcasts between 1941-1944. These broadcasts formed the basis for his book, "Mere Christianity." The BBC radio occurred in four series, beginning August 6, 1941 and ending April 4, 1944,and prior to the broadcasts, his work with the RAF began on April 9, 1941. The Screwtape Letters" (1942) first appeared in book form in February, of the year of this letter, 1942.