Omega
Omega: last letter of the Greek alphabet. This chapter begins at the end of the alphabet and therefore the circular structure of FW is invoked (O is also a circle).
Jesus said he was the "Alpha and Omega, the beginning and the end, the first and the last." (Revelation 22:13, KJV).
The beginning of this chapter is also in the shape of a delta: ∆ (a triangle). Delta is the fourth letter of the Greek alphabet. It is also the name given to the triangular shaped mouth of a river ie. the Nile Delta. The Delta represents Anna Livia's fertile uterus, from which all life flows. The opening letter '0' could therefore be an egg representing the beginning of life (and as Omega paradoxically the end-as-beginning). The '0' could also double as zero.
Prayers often begin with 'Oh...'
'Eau' is also French for 'water'.