In my writing, secondary characters are as important or almost anyway as the main protagonists. I love it when one shows up and proves to enrich every scene they're in. It's like a gift as those rich secondary characters give more dimensions to the hero and heroine.
I had one of those briefly in Arizona Dawn. He was an itinerant prospector who the hero, Rafe, didn't trust one bit. When he showed up a few years later in Lands of Fire, I was happy to finally get to know him better. I thought he'd be good for enriching the reader's understanding of the hero, but he proved better than I imagined and on multiple levels. Here's the scene when Jesse met him for the first time.
Lighting a cigarette, he didn’t bother with a lantern. A waxing moon was high enough in the sky to light the desert with a soft glow. Something rustled the rabbitbrush to Jesse’s right. Far in the distance, he heard the howl of a coyote and another answered from not far beyond his shed.
Until Jesse had come, this place had been theirs. Now, with him living in the adobe, putting a door back on it, his work on the corral, and increasing the size of the livestock lean-to, they had been pushed back. They didn’t like it. He didn’t blame them.
Bear growled. “Shhh boy,” he said, “I hear it.” He reached for his revolver on the barrel behind him. He never was far from a gun.
“You got any food, señor?” a man’s voice asked from the shadows.
Jesse rose. “Come closer where I can see you.”
“Your dog looks mean.” The voice was old.
“He is. So mind your business. Come out where the moonlight hits you.” A bearded old man, wearing a poncho walked slowly forward.
“Don’t hurt me, compadre.”
“Who are you?”
“Jose. I was gathering saguaro fruit. I got lost.”
The gathering part was possible—the accent not so much. “You have family nearby?”
“I do. They will be looking for me.”
“Jose, you are a liar.”
The old man edged closer as he nervously watched Bear. “He’s big. He bite?” he asked.
“Not if you stay where you are.” Jesse edged back in the adobe and brought out a lantern, which he set on the table and lit. “Come up here now and let me get a look at you.”
The old man came forward. “I did lie, but not about being hungry.”
“Why are you out here then? This is not near any villages. You have no horse.”
“I had a burro. She got away from me. You see her?”
Jesse smiled. “You really are a liar, aren’t you? And a poor one. What’s your real name? You aren’t Spanish, not with that accent, and don’t look Indian.”
When the man smiled, he revealed a mouth with few teeth. “What you doing out here, son?”