Which C.S. Lewis novel features the character Mark Studdock joining the N.I.C.E.?

That Hideous Strength features Mark Studdock joining the N.I.C.E., a powerful and sinister organization.

The novel is the third book of C.S. Lewis’s Space Trilogy, following Out of the Silent Planet and Perelandra. Unlike the earlier books, much of its action takes place on Earth, where scientific ambition, bureaucracy, and social power become central concerns.

Mark is an academic who is drawn into the N.I.C.E. because of its prestige and influence. His involvement contrasts with Jane Studdock’s experiences and with the novel’s wider supernatural conflict.

Readers sometimes identify the book with the planetary adventures of the first two trilogy volumes. Those settings belong mainly to Malacandra and Perelandra, whereas That Hideous Strength brings the trilogy’s conflict back to Earth.