The probe into corruption at Samsung and the Blue House – South Korea’s presidential palace – entered a new stage on Wednesday, with investigators racing to get to the bottom of last year’s shady merger between Samsung C&T and another Samsung affiliate, Cheil Industries.

A quick summary of what we already know: last year, Samsung donated $20 million to two entities, the Mir Foundation and K-Sports Foundation, that are linked to Choi Soon-sil, an intimate of President Park Geun-hye. Samsung also funneled sizable amounts of cash to Choi and her family through a German corporation she controls and even underwrote her teenage daughter’s pricey equestrian activities.

Why exactly did they fork over all this dough to Choi & co.? The working theory, in three words: quid pro quo. Try to follow this reaction pathway: Samsung bigwigs are believed to have bribed Choi to lean on her BFF, President Park, to order the National Pension Service – a major Samsung stockholder – to approve of the C&T/Chiel merger. The pension execs, as it happens, did indeed end up voting for the merger, even though their analysts had urged them to give it a thumbs-down.

In short, the guardians of South Korea’s retirement funds didn’t do what was best for retirees or for fellow C&T and Cheil stockholders (who, recognizing the merger as unfavorable to their interests, fiercely opposed the merger). They did what was best for the powers that be at Samsung, period. Especially Samsung vice chairman Lee Jae-yong.

At least that’s where the available evidence – largely acquired during a previous round of prosecutorial raids – seems to point. Now two investigative teams, one of them led by special independent counsel Park Young-soo, are intensifying the probe. On Wednesday, seeking further evidence, Park’s team – which has 70 days (with a 30-day extension if necessary) to complete its work – confiscated documents and hard drives at about ten locations, including the National Pension Service’s asset management office, the headquarters of the Ministry of Health and Welfare, and the homes of several Samsung executives.

That’s not all. The independent counsel has also secured an arrest warrant for Chung Yoo-rah, Choi’s horse-happy daughter, now 19. Since Chung is believed to be in Germany, the counsel has asked German officials to extradite her, has requested her German credit-card and phone records,  and has arranged for the cancellation of her passport. The investigators are even scrutinizing Chung’s high-school record, which turns out to have been faked. (The national educational department has already revoked her diploma.)

Meanwhile Lee – who, since his father, Lee Kung-hee, suffered a heart attack in May 2014, has been Samsung’s de facto top dog, and hence South Korea’s most powerful businessperson – has been barred from leaving the country. Earlier this month, the younger Lee testified at a parliamentary hearing that he didn’t know Choi and that Samsung’s payouts to her and her organizations were not bribes. According to one source, the independent counsel’s main goal is to find out whether or not that’s true.

The whole scandal is, of course, a huge blow to Samsung, South Korea’s largest conglomerate and the ultimate symbol of the nation’s postwar economic success. And it’s happening, note well, at a time when Samsung is still smarting from its exploding-phone fiasco.

So start the countdown: seventy days. For our part, we can’t wait to see what Park Young-soo and his colleagues dig up.