#StarTrek 38 (1967) - 9/10
The Changeling, written by #JohnMeredythLucas.

1️⃣ Good thriller, with an imaginative premise. The probe that the crew bring aboard the ship is basically a ticking bomb. Eventually it is going to turn on them and wipe them out. Waiting for that to happen is tense.

2️⃣ Excellent performance from #LeonardNimoy during the mind meld.

3️⃣ It may flag a bit in the middle, but the opening and closing acts are superb.