How to typeset this split voice?

[Christopher Culver]

I woud like to typeset the following score sample in Lilypond exactly
as it appears:

http://christopherculver.com/temp/score-example.png

Now, the vast majority of it is easy. (I simply did \new Staff for the
treble and the bass, then filled each of these with a few \new Voice
and marked them voiceOne, voiceTwo, etc.)

The problem, however, is the second treble voice from the top,
that starting on G. In the third bar, that voice splits into two as I
have circled in red. I'm not a complete Lilypond novice, but I'm
unsure how to organize that portion so that it appears just like in
the manuscript example. Could someone give me a few pointers?