Dark of night / Barbara Nickless.

Enhanced descriptions from Syndetics:

A recent murder is ancient history in a breathtaking novel about a sacred lost treasure and poisonous retribution by the Amazon Charts and Wall Street Journal bestselling author of At First Light .

What an exotic way to die in Chicago.

When esteemed historian Elizabeth Lawrence is found in her car, killed by a cobra's bite, only a brilliant professor of semiotics, Dr. Evan Wilding, can see the signs around her strange death. As he helps homicide detective Addie Bisset decipher the scene, the puzzles left behind offer Evan chilling passage into the mind of a killer.

Evan's investigation merges with that of an Israeli agent, who claims Elizabeth was close to acquiring an invaluable artifact. She was also drawing the attention of unsavory treasure hunters, forgers, and thieves. Was someone desperate to expose the truth of Elizabeth's astonishing discovery?

The deeper Evan and Addie delve into the case, the darker it gets. A murderer's archaic crimes are just the beginning. In a race where there can be only one winner, the final victim might be Evan.