Romans 3:23

I was working thru Romans 3:23-24 yesterday and found something that I
could not explain.
En the end of verse 24, Paul uses the construction
         --- dia tes apolutrowsis tes en Christwi Iesou.

What is the use or function of the second tes?  What does tes refer to?  How
should this construction be translated?  If I've parsed it correctly
(gen. sing. fem.), then it could refer to chariti or apolutrosis.
How is it (or is it?) connected to en Christwi?

| Christopher Walker                     Student  |"Chirpes: n, a canarial    |
| Trinity Evangelical Divinity School             | disease, no tweetment"    |
| Internet:CWALKER@apollo.roundlake.baxter.com    |                           |