Sherlock doesn't try to keep Howard in the cave, and doesn't explain himself when he leaves, but he keeps coming back. He's not sure exactly why, except that John told him to do it, and if John really was dead--

No. He immediately shut down that train of thought, scowling. No.

He distracted himself by keeping the fire at a steady, even blaze, though he sometimes threw a little sugar in just to watch the flames leap. He looked up when Howard came in, watched as he threw the animals down. Made a slight face, but skewered them with sticks he'd collected earlier and stuck the sticks into the ground, leaning over the flames.

He has absolutely no intention of eating any of it.

"Let me see your head." He asks every time Howard comes back.