question about subjunctive case

Here is a paragraph - the question is about the use of the word "were" in the sentence "But what if trolls were real?" Is "were" correct, or should it be: "But what if trolls are real?"

Trolls are fascinating creatures, figuring in fairy tales for hundreds of years. Descriptions of them range from small, merely mischievous beings to giant, violent monsters. But what if trolls were real? What if they hand down tales among themselves about us? And what if they live closer than we think?

Thanks for your help. I asked this on another board and the answers were evenly divided.