I don't think you can get an apartment in Upper Kirby (and in such a nice complex) for $839/month. It could be a come-on, bait-and-switch, or something similar ... note that the contact information is a (214) area code (that's the Dallas area), and that the actual address is not shown. It also appears that this "listing" has been on Trulia for over five months ... at that rent, it should have gone in less than an hour.
Information on sites such as this isn't always current. Your best bet is to search on http://www.har.com, where it's all up-to-date. I wouldn't begin looking in earnest until mid-May ... landlords aren't willing to hold an apartment, since the rental market is quite active. Rents in Upper Kirby should run well over $1000 for a one-bedroom unit.
Best of luck ...
I checked out the location on this apartment and see that you will not find one for this price. The one-bedrooms in this location are going for $1,500+.
When you are ready in June, let me know I can research and let you know what is available and what the price ranges are.