The exit of Thomas Cook Group CEO Manny Fontenla-Novoa will come as quite a shock to many given that he was always seen as a safe pair of hands.
Not many raised their eyebrows when in 2007 he was appointed group CEO of the newly formed Thomas Cook Group following the merger with fellow tour operating giant MyTravel - he had, after all, been CEO of Thomas Cook from 2003.
A Spaniard by birth who moved to the UK at an early age, Fontenla-Novoa was genuinely liked by many in the industry (as plenty of the comments here illustrate), was a talking head at endless European conferences and seen as an example of how someone could move up through the ranks to reach the top of the executive ladder (he started in the print room at Thomas Cook in 1972).
With a career in tour operating, covering Cook, International Leisure Group Sunworld and then back at Cook, what could go wrong for Fontenla-Novoa as he stepped in to oversee one of the biggest travel businesses in the world?
Clearly something did, as his exit today shows.
There are at least two schools of thought:
First is that Fontenla-Novoa was simply the right person at the wrong time. He may have been a popular figure, but within a year of the merger of Thomas Cook with MyTravel the economy had already started to show signs of problems ahead.
Over the next few years, pressures on the business led to job losses and retail shop closures as consumers either tightened their belts and opted for cheaper holidays or tried other methods of taking a trip, opting for different products from Cook's core package holiday business.
The company's London-listed shares held reasonably steady until April 2010, when the price started its downward spiral to where it is now at 64p - down from close to 320p at the time of the merger.
Fontenla-Novoa could simply be doing the honourable thing and leaving the business as, on his watch, financial performance for shareholders has not been great, spanked by an economic crisis that is still showing no sign of letting up.
This doesn't exactly chime with what has happened at arch rival TUI Travel, where the share price is still two-thirds of what it was when it merged with First Choice around the same time.
So then there is perhaps the wider strategy.
For Thomas Cook, brand is everything. It has 170 years of history in travel and is one of the biggest names in the business, especially since the 1970s when it pioneered the package holiday.
Since the mid-2000s, however, it has continued to push the package holiday part of the business, talk up the classic retail agent-operator relationship, while others around it have moved into new areas, trying models and products where there is arguably better growth.
Fontenla-Novoa has always been correct in that there is plenty of life and value in the retail model and advantages to owning assets such as aircraft, but some might argue that it isn't the only route in a much more dynamic marketplace.
As one industry figure remarked earlier today,"doesn't matter how good the skipper of the oil tanker is when everyone else is investing in renewable energy," implying that Cook's determination to stay on the traditional path made it more difficult to change when perhaps it needed to.
Technology is part of the issue.
While a brand such as EasyJet was overhauling its non-air product to become a major online travel seller across Europe, Thomas Cook was trying to merge with fellow, predominantly offline retail outfit Co-Operative Travel Group.
Meanwhile, under Fontenla-Novoa's watch, Thomas Cook also had to deal with the debacle surrounding the failure of its reservation system supplier BlueSky Technologies.
The handling of that particular issue was, according to one senior figure, a "mess in itself which was then mishandled further by Thomas Cook right up to the top".
Interestingly, Thomas Cook still refuses to disclose exactly how much it has spent on the infamous Globe project since the saga began in 2007, but some figures bandied around would be enough to make any investor's eyes water.
The issue is still not resolved, with former-BlueSky employees battling with Thomas Cook for compensation.
Fast forward to 2010 and some talked of a change in approach and thinking at Thomas Cook, when in June the company outlined a strategy to evolve its web presence into a wider, online travel agency-type business.
A dedicated division was created in London and a steady stream of people have joined from around the industry.
Unfortunately, Fontenla-Novoa was perhaps always going to find his "rival to Expedia" promise might haunt him, despite saying from the beginning that the project would take three years to compete.
The company has continually said the OTA is performing in line with its schedule, although some of those on the inside say it is actually taking "a little longer than expected".
Three years is a long time in travel, as everyone knows.
But perhaps it isn't the length of time to get the OTA to operating fully that is the issue, but more that it took Thomas Cook so long to come up with the idea in the first place, while others around Europe such as Expedia, eDreams et al secured strong positions.
It is this issue in particular that resonates the most with those watching from the outside. Culturally, like the captain of the tanker, Thomas Cook may simply not have had the motivation to evolve at the speed it perhaps needed to.
This may perplex some, as the company had the potential to capture some of the enthusiasm for a new world through the merger with MyTravel. As early as 2000, boss of MyTravel predecessor Airtours, David Crossland was talking of:

"...a holistic approach, which integrates distribution and customer relationship management with appropriate content and product, encompassing the multitude of distribution channels... including interactive TV, mobile technology, the internet, call centres and the high street".
This may have filtered through into the newly formed Thomas Cook Group PLC, but it clearly wasn't the number one priority.
And perhaps this is one of the reasons, in the wider context, why Fontenla-Novoa has stepped down. Culture is, after all, driven by leadership.
NB: Picture from a YouTube clip of the Disney show Handy Manny.