Possible Plumbing Problem

[eleanorigby]

After a rain (more than a drizzle, but doesn't have to be a big downpour), I am noticing the smell of sewer gas in the basement (only in the basement). The basement is dry (trust me, I do check like an obsessed person after a major backup one week after I moved into this interesting abode).

Do I call a plumber and pay minimum $100 for them to cross my threshold before any evaluation or work?

Pouring water down the floor drain does nothing.

I deeply fear a crack in the stack... but I also don't want my brain poisoned by sewer gas (if that's a thing. That's a thing, right?)

Thank you in advance.