Need to plot one series on top of another

In the attached file, I have several X-Y scatter plots, each of which is a plot of two series. One series is plotted with green X's and no line, while the other series is plotted as a blue line with no markers. I can't get the blue line to plot on top of the green X's. I tried changing the order of the series under the "Select Data" menu, but it still puts the green X's on top of the blue line. Can someone tell me how to get the series with the blue line to plot on top of the green X's? (i.e., I want the blue line to always be visible, even when the green X's have similar values). Thanks!