was going okay till ep 4 .... but i am going to skip to the final episode
edit - okay so i skipped to the final episode and found that the female lead too gets into the spying industry, a source to be specific and her ex husband and her do a mission together and after it's success they drink wine, talk and see their fortunes and the episode ends with them kissing, maybe the feelings are rekindled.
meanwhile fl's husband is alive (he was a spy too and was declared dead) and fl comes across him thinking it's a coincidence (they don't meet or talk tho) but it is not ! when she recognizes him she runs after him but he disappears but before disappearing he leaves a pin (used by dressmakers to pin fabrics) on fl's coffee table.

so even if you skip a few episodes from the mid of the series you won't miss too much.