For centuries, people have used art to tell stories. But the paintings of Roy Lichtenstein don’t tell a full story: they plop you right into the climax, and you’re left unsure of the characters, conflicts or solutions.

Lichtenstein, one of America’s most famous pop artists, pushed the boundaries of what Americans considered art, making large paintings that look like (and are often based off) frames from comic books, complete with dots, hard lines and speech bubbles. Lichtenstein’s work is on display at the National Gallery of Art until Jan. 13 in “Roy Lichtenstein, a Retrospective,” the first showing of his work after his death in 1997.

It can be a bit of a shock to walk through the National Gallery past regal portraits, heroic war scenes and stunning landscapes then suddenly arrive at a giant painting of a cartoonized hotdog. Thoughts like “what is this?” and “ Is this fine art?” invariably arise in the mind of any passerby. These same questions pummeled Lichtenstein during his lifetime (1923-1997). People didn’t know what to make of his controversial work.

The gallery takes you through several phases of Lichtenstein’s art, starting with his early work of seemingly random objects and still lifes, simplified and enlarged. Then the gallery moves on to his romances, which contains some of his most famous paintings, like “Crying Girl.”

The paintings show large images of girls’ faces, sometimes accompanied by men, with emotional speech bubbles. Lichtenstein takes many of the subjects of his paintings out of the climax of a comic strip, leaving out the superfluous beginnings and endings. The same is true for his war paintings, where sometimes all we are left with is the “BANG.”

At first this leaves you with a feeling of discontent. Who is this Brad, or Jeff, or the unnamed enemy being fought, and what did he do to cause the action? Although I looked for clues within the paintings to the true source of the conflict, there’s no readily available answer. A perpetual tease, Lichtenstein never lets us see the rest of the comic.

But as I moved father into the exhibit, I started to like the vagueness of Lichtenstein’s paintings, which allow the viewer to make of the scene whatever she wants. Lichtenstein’s work may be unconventional, highly unusual and far from what most of us would consider fine art, but it sure is fun to look at.