“All the Light We Cannot See” is not, in the strictest sense, a comfort watch. Like the Pulitzer Prize-winning Anthony Doerr novel on which it’s based, the four-episode limited series takes place in a walled city under siege by a bombing campaign, its trapped civilians unable to evacuate — hardly a relaxing break from today’s headlines. But the Netflix show is, in a way, a return to simpler times. This particular walled city is located in Nazi-occupied France, on the verge of American liberation in August 1944. As written, “All the Light We Cannot See” is already set amid a...