Billionaire investor Nelson Peltz has stepped up to the counter at Starbucks, taking a stake in the company.

In announcing his return Monday as chief executive officer at Starbucks, Howard Schultz would seem to be telling his company to wake up and smell the coffee.

Calling for a renewed emphasis on the ambiance that made the chain distinctive before it became a coffee giant, Schultz joins the ranks of charismatic CEOs, most notably Steve Jobs at Apple Inc., who couldn’t stand aside as their companies hit troubled times.