here. After crossing over the last section from the bottom and dropping off the last section from the top, you will have only two pieces left to work with. You can combine them together and pull them back an inch or two. Lift up some hair from the top of the head. Use two bobby pins to hold down the strand from the braid (in an X shape). Let the top hair fall down hiding the bobby pins. If you find that the bobby pins stick out and show, try using mini bobbies instead.
Or, instead of combining the last two strands, you can draw up another for three strands again, and do a simple braid for a few inches. You can bobby pin it like above, or anchor it with another piece of hair and a rubber band like in this post, but hiding it beneath some loose hair.