Every summer, some character from a past blockbuster comes back to entertain yet again. They tease with the notion that this time will be just as thrilling as the last — but usually disappoint.

Last year it was Indiana Jones. This year, it’s Eminem’s Slim Shady.

Rap’s demented antihero — the star of Eminem’s best-selling CDs and biggest hits — has returned to torment us once again on “Relapse,” Eminem’s first full studio album in almost five years.

“I guess it’s time for you to hate me again/Let’s begin, now hand me the pen,” he chants in the refrain of “Medicine Ball,” a nonsensical ode to menacing behavior that includes everything from a Christopher Reeve insult to pill-popping references.

The problem is, what “Relapse” inspires more than hate is indifference. When Eminem and his alter-ego Slim Shady made their debut a decade ago, not only were the raps a lot wittier, they also introduced us to a sinister darkness that was shocking and revelatory at the same time: We felt as if we were getting an insider’s view of a tormented soul gleefully upending society.

Four albums later, we get the picture. Adding new layers of gore, misogyny and hateful epithets doesn’t make it any fresher, especially if the rhymes are progressively weaker. “Bagpipes from Baghdad” skewers Mariah Carey, but wasn’t that so 2003? Is Marshall Mathers still carrying a torch for Ms. Carey? And does anyone care?