FOR more than two years, and especially over the last few weeks, the Alex Salmond inquiry has been a rollercoaster - unpredictable, startling and prone to wild, dizzying changes of direction.

After Nicola Sturgeon’s evidence yesterday, that rollercoaster seems to be slowing to a halt.

Over eight hours, the First Minister took on all the most damaging allegations against her and brushed most of them aside with little apparent effort.

By the end, she seemed more tired than rattled; the claims more niggles than bombshells.

She certainly had awkward moments.

Some of her explanations were met with well-earned scepticism, especially on areas relating to whether she had breached the ministerial code.

She also failed to answer the question at the heart of the inquiry – why the wrong person was appointed to investigate sexual misconduct claims against Mr Salmond, and why it took almost a year for the penny to drop.

The late disclosure of key facts about this to a court was, she admitted, “catastrophic” and a key factor in the crumbling of the Government’s defence of Mr Salmond’s civil case.

But why had so much gone so wrong?

“I can’t say why it took so long for that information to come to light,” she said, almost in passing.

She was also rightly criticised for the Government’s mulish lack of co-operation with the inquiry, and the withholding of key documents.

However, there was no knock-out blow, no tongue-tied moment of guilt, and the opposition parties left without the scalp they hoped to parade into May’s election, although the impression of a secretive government with something to hide might last.

Her technique was simple: stick to everything she had already said; offer simple, pedestrian explanations for the unrelated threads in Mr Salmond’s conspiracy tapestry; and just be more human than her predecessor.

While he was coolly methodical last week and refused to apologise for his actions, Ms Sturgeon apologised for her mistakes and those of the Government, and let her emotions show through.

At various times, her voice broke and she had to stop close to tears, and what was most devastating was these moments came when she spoke warmly of Mr Salmond.

They had been "besties", she joked. She had revered him, cared for him, campaigned for him, worked for him, seen him as a friend.

Yet all that seemed to count for nothing now as he showed no remorse and accused his former colleagues of plotting his destruction to avoid facing up to his own conduct.

He might well say the same of her, but she displayed an empathy his testimony visibly lacked.

The rollercoaster could still throw up a few late surprises.

Messages between senior SNP figures, which Mr Salmond says prove a plot, have yet to come out.

There is FMQs today, and the Sunday newspapers might unearth more nuggets.

Mr Salmond's announcement mid-evidence that he had lodged a complaint over a possible leak alsos shows he isn't going anywhere quietly.

Most ominously for the First Minister, the independent adviser on the Scottish Ministerial Code will soon report on his parallel investigation into whether she was guilty of a serious ethics breach.

If he finds she broke the code, and in particular that she lied to parliament, that alone could be enough to force her resignation, regardless of the inquiry’s work.