The Shroud of Turin — K.T. Tomb

In the seventh exciting novel of this treasure-hunting series, Simon Kessler sends Thalia Phoenix and her cousin, Casey, to a New York museum to examine the writing on a papyrus document. However, before they can carry out their assignment, Phoe and Casey are kidnapped by a villain who demands that she locate the real shroud-Casey will be held hostage until Phoe finds it.