Fynn recounts his time spent with Anna, and gives a very personal account of her outpourings on life, mathematics, science and her mentor, Mister God.

While roaming the docks at night, the author comes across a small girl sitting on the grating below a shop window.

Unable to find out where she came from, Fynn takes the child home, only to discover she is an abused runaway.

The ending of the book describes Anna's death at age seven after falling from a tree and Fynn's profound grief.

Sydney George Hopkins (26 March 1919 - 3 July 1999), as a teenager and young adult, lived in the East End of London in the early 1930s.

[6] Following a fall off a cliff he suffered chronic insomnia and in 1939 was referred to Finchden Manor[7] in Kent, a therapeutic community run by George Lyward O.B.E., and later joined the staff.

[8] Theologian Vernon Sproxton commented that Hopkins' "most formative thinking took place far from the quads and colleges and punted rivers amongst the small streets, warehouses, and canals of the East End.

In his preface to both the British and American editions of the book, Vernon Sproxton remarks that he has seen Anna's drawings and notes and that he believes her to be real.